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-rw-r--r--kernel/cgroup.c1660
-rw-r--r--kernel/cgroup_freezer.c155
-rw-r--r--kernel/cpu.c9
-rw-r--r--kernel/cpuset.c317
-rw-r--r--kernel/events/core.c29
-rw-r--r--kernel/fork.c5
-rw-r--r--kernel/hung_task.c13
-rw-r--r--kernel/lglock.c12
-rw-r--r--kernel/mutex.c43
-rw-r--r--kernel/nsproxy.c27
-rw-r--r--kernel/pid_namespace.c4
-rw-r--r--kernel/power/suspend.c4
-rw-r--r--kernel/printk/printk.c7
-rw-r--r--kernel/rcu.h12
-rw-r--r--kernel/rcupdate.c102
-rw-r--r--kernel/rcutiny.c2
-rw-r--r--kernel/rcutiny_plugin.h2
-rw-r--r--kernel/rcutorture.c396
-rw-r--r--kernel/rcutree.c255
-rw-r--r--kernel/rcutree.h19
-rw-r--r--kernel/rcutree_plugin.h460
-rw-r--r--kernel/sched/core.c113
-rw-r--r--kernel/sched/cpuacct.c51
-rw-r--r--kernel/sched/sched.h6
-rw-r--r--kernel/smp.c2
-rw-r--r--kernel/time/Kconfig50
-rw-r--r--kernel/trace/trace.h3
-rw-r--r--kernel/trace/trace_printk.c19
-rw-r--r--kernel/workqueue.c50
29 files changed, 2236 insertions, 1591 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 781845a013ab..e0aeb32415ff 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -81,7 +81,7 @@
*/
#ifdef CONFIG_PROVE_RCU
DEFINE_MUTEX(cgroup_mutex);
-EXPORT_SYMBOL_GPL(cgroup_mutex); /* only for task_subsys_state_check() */
+EXPORT_SYMBOL_GPL(cgroup_mutex); /* only for lockdep */
#else
static DEFINE_MUTEX(cgroup_mutex);
#endif
@@ -117,6 +117,7 @@ struct cfent {
struct list_head node;
struct dentry *dentry;
struct cftype *type;
+ struct cgroup_subsys_state *css;
/* file xattrs */
struct simple_xattrs xattrs;
@@ -159,9 +160,9 @@ struct css_id {
*/
struct cgroup_event {
/*
- * Cgroup which the event belongs to.
+ * css which the event belongs to.
*/
- struct cgroup *cgrp;
+ struct cgroup_subsys_state *css;
/*
* Control file which the event associated.
*/
@@ -215,10 +216,33 @@ static u64 cgroup_serial_nr_next = 1;
*/
static int need_forkexit_callback __read_mostly;
-static void cgroup_offline_fn(struct work_struct *work);
+static struct cftype cgroup_base_files[];
+
+static void cgroup_destroy_css_killed(struct cgroup *cgrp);
static int cgroup_destroy_locked(struct cgroup *cgrp);
-static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
- struct cftype cfts[], bool is_add);
+static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],
+ bool is_add);
+
+/**
+ * cgroup_css - obtain a cgroup's css for the specified subsystem
+ * @cgrp: the cgroup of interest
+ * @ss: the subsystem of interest (%NULL returns the dummy_css)
+ *
+ * Return @cgrp's css (cgroup_subsys_state) associated with @ss. This
+ * function must be called either under cgroup_mutex or rcu_read_lock() and
+ * the caller is responsible for pinning the returned css if it wants to
+ * keep accessing it outside the said locks. This function may return
+ * %NULL if @cgrp doesn't have @subsys_id enabled.
+ */
+static struct cgroup_subsys_state *cgroup_css(struct cgroup *cgrp,
+ struct cgroup_subsys *ss)
+{
+ if (ss)
+ return rcu_dereference_check(cgrp->subsys[ss->subsys_id],
+ lockdep_is_held(&cgroup_mutex));
+ else
+ return &cgrp->dummy_css;
+}
/* convenient tests for these bits */
static inline bool cgroup_is_dead(const struct cgroup *cgrp)
@@ -365,9 +389,11 @@ static struct cgrp_cset_link init_cgrp_cset_link;
static int cgroup_init_idr(struct cgroup_subsys *ss,
struct cgroup_subsys_state *css);
-/* css_set_lock protects the list of css_set objects, and the
- * chain of tasks off each css_set. Nests outside task->alloc_lock
- * due to cgroup_iter_start() */
+/*
+ * css_set_lock protects the list of css_set objects, and the chain of
+ * tasks off each css_set. Nests outside task->alloc_lock due to
+ * css_task_iter_start().
+ */
static DEFINE_RWLOCK(css_set_lock);
static int css_set_count;
@@ -392,10 +418,12 @@ static unsigned long css_set_hash(struct cgroup_subsys_state *css[])
return key;
}
-/* We don't maintain the lists running through each css_set to its
- * task until after the first call to cgroup_iter_start(). This
- * reduces the fork()/exit() overhead for people who have cgroups
- * compiled into their kernel but not actually in use */
+/*
+ * We don't maintain the lists running through each css_set to its task
+ * until after the first call to css_task_iter_start(). This reduces the
+ * fork()/exit() overhead for people who have cgroups compiled into their
+ * kernel but not actually in use.
+ */
static int use_task_css_set_links __read_mostly;
static void __put_css_set(struct css_set *cset, int taskexit)
@@ -464,7 +492,7 @@ static inline void put_css_set_taskexit(struct css_set *cset)
* @new_cgrp: cgroup that's being entered by the task
* @template: desired set of css pointers in css_set (pre-calculated)
*
- * Returns true if "cg" matches "old_cg" except for the hierarchy
+ * Returns true if "cset" matches "old_cset" except for the hierarchy
* which "new_cgrp" belongs to, for which it should match "new_cgrp".
*/
static bool compare_css_sets(struct css_set *cset,
@@ -555,7 +583,7 @@ static struct css_set *find_existing_css_set(struct css_set *old_cset,
/* Subsystem is in this hierarchy. So we want
* the subsystem state from the new
* cgroup */
- template[i] = cgrp->subsys[i];
+ template[i] = cgroup_css(cgrp, ss);
} else {
/* Subsystem is not in this hierarchy, so we
* don't want to change the subsystem state */
@@ -803,8 +831,7 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task,
static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry);
-static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files,
- unsigned long subsys_mask);
+static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask);
static const struct inode_operations cgroup_dir_inode_operations;
static const struct file_operations proc_cgroupstats_operations;
@@ -813,8 +840,7 @@ static struct backing_dev_info cgroup_backing_dev_info = {
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
-static int alloc_css_id(struct cgroup_subsys *ss,
- struct cgroup *parent, struct cgroup *child);
+static int alloc_css_id(struct cgroup_subsys_state *child_css);
static struct inode *cgroup_new_inode(umode_t mode, struct super_block *sb)
{
@@ -845,15 +871,8 @@ static struct cgroup_name *cgroup_alloc_name(struct dentry *dentry)
static void cgroup_free_fn(struct work_struct *work)
{
struct cgroup *cgrp = container_of(work, struct cgroup, destroy_work);
- struct cgroup_subsys *ss;
mutex_lock(&cgroup_mutex);
- /*
- * Release the subsystem state objects.
- */
- for_each_root_subsys(cgrp->root, ss)
- ss->css_free(cgrp);
-
cgrp->root->number_of_cgroups--;
mutex_unlock(&cgroup_mutex);
@@ -864,8 +883,6 @@ static void cgroup_free_fn(struct work_struct *work)
*/
dput(cgrp->parent->dentry);
- ida_simple_remove(&cgrp->root->cgroup_ida, cgrp->id);
-
/*
* Drop the active superblock reference that we took when we
* created the cgroup. This will free cgrp->root, if we are
@@ -956,27 +973,22 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
}
/**
- * cgroup_clear_directory - selective removal of base and subsystem files
- * @dir: directory containing the files
- * @base_files: true if the base files should be removed
+ * cgroup_clear_dir - remove subsys files in a cgroup directory
+ * @cgrp: target cgroup
* @subsys_mask: mask of the subsystem ids whose files should be removed
*/
-static void cgroup_clear_directory(struct dentry *dir, bool base_files,
- unsigned long subsys_mask)
+static void cgroup_clear_dir(struct cgroup *cgrp, unsigned long subsys_mask)
{
- struct cgroup *cgrp = __d_cgrp(dir);
struct cgroup_subsys *ss;
+ int i;
- for_each_root_subsys(cgrp->root, ss) {
+ for_each_subsys(ss, i) {
struct cftype_set *set;
- if (!test_bit(ss->subsys_id, &subsys_mask))
+
+ if (!test_bit(i, &subsys_mask))
continue;
list_for_each_entry(set, &ss->cftsets, node)
- cgroup_addrm_files(cgrp, NULL, set->cfts, false);
- }
- if (base_files) {
- while (!list_empty(&cgrp->files))
- cgroup_rm_file(cgrp, NULL);
+ cgroup_addrm_files(cgrp, set->cfts, false);
}
}
@@ -986,9 +998,6 @@ static void cgroup_clear_directory(struct dentry *dir, bool base_files,
static void cgroup_d_remove_dir(struct dentry *dentry)
{
struct dentry *parent;
- struct cgroupfs_root *root = dentry->d_sb->s_fs_info;
-
- cgroup_clear_directory(dentry, true, root->subsys_mask);
parent = dentry->d_parent;
spin_lock(&parent->d_lock);
@@ -1009,79 +1018,84 @@ static int rebind_subsystems(struct cgroupfs_root *root,
{
struct cgroup *cgrp = &root->top_cgroup;
struct cgroup_subsys *ss;
- int i;
+ unsigned long pinned = 0;
+ int i, ret;
BUG_ON(!mutex_is_locked(&cgroup_mutex));
BUG_ON(!mutex_is_locked(&cgroup_root_mutex));
/* Check that any added subsystems are currently free */
for_each_subsys(ss, i) {
- unsigned long bit = 1UL << i;
-
- if (!(bit & added_mask))
+ if (!(added_mask & (1 << i)))
continue;
+ /* is the subsystem mounted elsewhere? */
if (ss->root != &cgroup_dummy_root) {
- /* Subsystem isn't free */
- return -EBUSY;
+ ret = -EBUSY;
+ goto out_put;
+ }
+
+ /* pin the module */
+ if (!try_module_get(ss->module)) {
+ ret = -ENOENT;
+ goto out_put;
}
+ pinned |= 1 << i;
}
- /* Currently we don't handle adding/removing subsystems when
- * any child cgroups exist. This is theoretically supportable
- * but involves complex error handling, so it's being left until
- * later */
- if (root->number_of_cgroups > 1)
- return -EBUSY;
+ /* subsys could be missing if unloaded between parsing and here */
+ if (added_mask != pinned) {
+ ret = -ENOENT;
+ goto out_put;
+ }
+
+ ret = cgroup_populate_dir(cgrp, added_mask);
+ if (ret)
+ goto out_put;
+
+ /*
+ * Nothing can fail from this point on. Remove files for the
+ * removed subsystems and rebind each subsystem.
+ */
+ cgroup_clear_dir(cgrp, removed_mask);
- /* Process each subsystem */
for_each_subsys(ss, i) {
unsigned long bit = 1UL << i;
if (bit & added_mask) {
/* We're binding this subsystem to this hierarchy */
- BUG_ON(cgrp->subsys[i]);
- BUG_ON(!cgroup_dummy_top->subsys[i]);
- BUG_ON(cgroup_dummy_top->subsys[i]->cgroup != cgroup_dummy_top);
+ BUG_ON(cgroup_css(cgrp, ss));
+ BUG_ON(!cgroup_css(cgroup_dummy_top, ss));
+ BUG_ON(cgroup_css(cgroup_dummy_top, ss)->cgroup != cgroup_dummy_top);
+
+ rcu_assign_pointer(cgrp->subsys[i],
+ cgroup_css(cgroup_dummy_top, ss));
+ cgroup_css(cgrp, ss)->cgroup = cgrp;
- cgrp->subsys[i] = cgroup_dummy_top->subsys[i];
- cgrp->subsys[i]->cgroup = cgrp;
list_move(&ss->sibling, &root->subsys_list);
ss->root = root;
if (ss->bind)
- ss->bind(cgrp);
+ ss->bind(cgroup_css(cgrp, ss));
/* refcount was already taken, and we're keeping it */
root->subsys_mask |= bit;
} else if (bit & removed_mask) {
/* We're removing this subsystem */
- BUG_ON(cgrp->subsys[i] != cgroup_dummy_top->subsys[i]);
- BUG_ON(cgrp->subsys[i]->cgroup != cgrp);
+ BUG_ON(cgroup_css(cgrp, ss) != cgroup_css(cgroup_dummy_top, ss));
+ BUG_ON(cgroup_css(cgrp, ss)->cgroup != cgrp);
if (ss->bind)
- ss->bind(cgroup_dummy_top);
- cgroup_dummy_top->subsys[i]->cgroup = cgroup_dummy_top;
- cgrp->subsys[i] = NULL;
+ ss->bind(cgroup_css(cgroup_dummy_top, ss));
+
+ cgroup_css(cgroup_dummy_top, ss)->cgroup = cgroup_dummy_top;
+ RCU_INIT_POINTER(cgrp->subsys[i], NULL);
+
cgroup_subsys[i]->root = &cgroup_dummy_root;
list_move(&ss->sibling, &cgroup_dummy_root.subsys_list);
/* subsystem is now free - drop reference on module */
module_put(ss->module);
root->subsys_mask &= ~bit;
- } else if (bit & root->subsys_mask) {
- /* Subsystem state should already exist */
- BUG_ON(!cgrp->subsys[i]);
- /*
- * a refcount was taken, but we already had one, so
- * drop the extra reference.
- */
- module_put(ss->module);
-#ifdef CONFIG_MODULE_UNLOAD
- BUG_ON(ss->module && !module_refcount(ss->module));
-#endif
- } else {
- /* Subsystem state shouldn't exist */
- BUG_ON(cgrp->subsys[i]);
}
}
@@ -1092,6 +1106,12 @@ static int rebind_subsystems(struct cgroupfs_root *root,
root->flags |= CGRP_ROOT_SUBSYS_BOUND;
return 0;
+
+out_put:
+ for_each_subsys(ss, i)
+ if (pinned & (1 << i))
+ module_put(ss->module);
+ return ret;
}
static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry)
@@ -1142,7 +1162,6 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
char *token, *o = data;
bool all_ss = false, one_ss = false;
unsigned long mask = (unsigned long)-1;
- bool module_pin_failed = false;
struct cgroup_subsys *ss;
int i;
@@ -1285,52 +1304,9 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
if (!opts->subsys_mask && !opts->name)
return -EINVAL;
- /*
- * Grab references on all the modules we'll need, so the subsystems
- * don't dance around before rebind_subsystems attaches them. This may
- * take duplicate reference counts on a subsystem that's already used,
- * but rebind_subsystems handles this case.
- */
- for_each_subsys(ss, i) {
- if (!(opts->subsys_mask & (1UL << i)))
- continue;
- if (!try_module_get(cgroup_subsys[i]->module)) {
- module_pin_failed = true;
- break;
- }
- }
- if (module_pin_failed) {
- /*
- * oops, one of the modules was going away. this means that we
- * raced with a module_delete call, and to the user this is
- * essentially a "subsystem doesn't exist" case.
- */
- for (i--; i >= 0; i--) {
- /* drop refcounts only on the ones we took */
- unsigned long bit = 1UL << i;
-
- if (!(bit & opts->subsys_mask))
- continue;
- module_put(cgroup_subsys[i]->module);
- }
- return -ENOENT;
- }
-
return 0;
}
-static void drop_parsed_module_refcounts(unsigned long subsys_mask)
-{
- struct cgroup_subsys *ss;
- int i;
-
- mutex_lock(&cgroup_mutex);
- for_each_subsys(ss, i)
- if (subsys_mask & (1UL << i))
- module_put(cgroup_subsys[i]->module);
- mutex_unlock(&cgroup_mutex);
-}
-
static int cgroup_remount(struct super_block *sb, int *flags, char *data)
{
int ret = 0;
@@ -1370,22 +1346,15 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
goto out_unlock;
}
- /*
- * Clear out the files of subsystems that should be removed, do
- * this before rebind_subsystems, since rebind_subsystems may
- * change this hierarchy's subsys_list.
- */
- cgroup_clear_directory(cgrp->dentry, false, removed_mask);
-
- ret = rebind_subsystems(root, added_mask, removed_mask);
- if (ret) {
- /* rebind_subsystems failed, re-populate the removed files */
- cgroup_populate_dir(cgrp, false, removed_mask);
+ /* remounting is not allowed for populated hierarchies */
+ if (root->number_of_cgroups > 1) {
+ ret = -EBUSY;
goto out_unlock;
}
- /* re-populate subsystem files */
- cgroup_populate_dir(cgrp, false, added_mask);
+ ret = rebind_subsystems(root, added_mask, removed_mask);
+ if (ret)
+ goto out_unlock;
if (opts.release_agent)
strcpy(root->release_agent_path, opts.release_agent);
@@ -1395,8 +1364,6 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
- if (ret)
- drop_parsed_module_refcounts(opts.subsys_mask);
return ret;
}
@@ -1416,6 +1383,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
INIT_LIST_HEAD(&cgrp->release_list);
INIT_LIST_HEAD(&cgrp->pidlists);
mutex_init(&cgrp->pidlist_mutex);
+ cgrp->dummy_css.cgroup = cgrp;
INIT_LIST_HEAD(&cgrp->event_list);
spin_lock_init(&cgrp->event_list_lock);
simple_xattrs_init(&cgrp->xattrs);
@@ -1431,6 +1399,7 @@ static void init_cgroup_root(struct cgroupfs_root *root)
cgrp->root = root;
RCU_INIT_POINTER(cgrp->name, &root_cgroup_name);
init_cgroup_housekeeping(cgrp);
+ idr_init(&root->cgroup_idr);
}
static int cgroup_init_root_id(struct cgroupfs_root *root, int start, int end)
@@ -1503,7 +1472,6 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
*/
root->subsys_mask = opts->subsys_mask;
root->flags = opts->flags;
- ida_init(&root->cgroup_ida);
if (opts->release_agent)
strcpy(root->release_agent_path, opts->release_agent);
if (opts->name)
@@ -1519,7 +1487,7 @@ static void cgroup_free_root(struct cgroupfs_root *root)
/* hierarhcy ID shoulid already have been released */
WARN_ON_ONCE(root->hierarchy_id);
- ida_destroy(&root->cgroup_ida);
+ idr_destroy(&root->cgroup_idr);
kfree(root);
}
}
@@ -1584,7 +1552,9 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
int ret = 0;
struct super_block *sb;
struct cgroupfs_root *new_root;
+ struct list_head tmp_links;
struct inode *inode;
+ const struct cred *cred;
/* First find the desired set of subsystems */
mutex_lock(&cgroup_mutex);
@@ -1600,7 +1570,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
new_root = cgroup_root_from_opts(&opts);
if (IS_ERR(new_root)) {
ret = PTR_ERR(new_root);
- goto drop_modules;
+ goto out_err;
}
opts.new_root = new_root;
@@ -1609,17 +1579,15 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
if (IS_ERR(sb)) {
ret = PTR_ERR(sb);
cgroup_free_root(opts.new_root);
- goto drop_modules;
+ goto out_err;
}
root = sb->s_fs_info;
BUG_ON(!root);
if (root == opts.new_root) {
/* We used the new root structure, so this is a new hierarchy */
- struct list_head tmp_links;
struct cgroup *root_cgrp = &root->top_cgroup;
struct cgroupfs_root *existing_root;
- const struct cred *cred;
int i;
struct css_set *cset;
@@ -1634,6 +1602,11 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
mutex_lock(&cgroup_mutex);
mutex_lock(&cgroup_root_mutex);
+ root_cgrp->id = idr_alloc(&root->cgroup_idr, root_cgrp,
+ 0, 1, GFP_KERNEL);
+ if (root_cgrp->id < 0)
+ goto unlock_drop;
+
/* Check for name clashes with existing mounts */
ret = -EBUSY;
if (strlen(root->name))
@@ -1657,26 +1630,37 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
if (ret)
goto unlock_drop;
+ sb->s_root->d_fsdata = root_cgrp;
+ root_cgrp->dentry = sb->s_root;
+
+ /*
+ * We're inside get_sb() and will call lookup_one_len() to
+ * create the root files, which doesn't work if SELinux is
+ * in use. The following cred dancing somehow works around
+ * it. See 2ce9738ba ("cgroupfs: use init_cred when
+ * populating new cgroupfs mount") for more details.
+ */
+ cred = override_creds(&init_cred);
+
+ ret = cgroup_addrm_files(root_cgrp, cgroup_base_files, true);
+ if (ret)
+ goto rm_base_files;
+
ret = rebind_subsystems(root, root->subsys_mask, 0);
- if (ret == -EBUSY) {
- free_cgrp_cset_links(&tmp_links);
- goto unlock_drop;
- }
+ if (ret)
+ goto rm_base_files;
+
+ revert_creds(cred);
+
/*
* There must be no failure case after here, since rebinding
* takes care of subsystems' refcounts, which are explicitly
* dropped in the failure exit path.
*/
- /* EBUSY should be the only error here */
- BUG_ON(ret);
-
list_add(&root->root_list, &cgroup_roots);
cgroup_root_count++;
- sb->s_root->d_fsdata = root_cgrp;
- root->top_cgroup.dentry = sb->s_root;
-
/* Link the top cgroup in this hierarchy into all
* the css_set objects */
write_lock(&css_set_lock);
@@ -1689,9 +1673,6 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
BUG_ON(!list_empty(&root_cgrp->children));
BUG_ON(root->number_of_cgroups != 1);
- cred = override_creds(&init_cred);
- cgroup_populate_dir(root_cgrp, true, root->subsys_mask);
- revert_creds(cred);
mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
mutex_unlock(&inode->i_mutex);
@@ -1711,15 +1692,16 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
pr_warning("cgroup: new mount options do not match the existing superblock, will be ignored\n");
}
}
-
- /* no subsys rebinding, so refcounts don't change */
- drop_parsed_module_refcounts(opts.subsys_mask);
}
kfree(opts.release_agent);
kfree(opts.name);
return dget(sb->s_root);
+ rm_base_files:
+ free_cgrp_cset_links(&tmp_links);
+ cgroup_addrm_files(&root->top_cgroup, cgroup_base_files, false);
+ revert_creds(cred);
unlock_drop:
cgroup_exit_root_id(root);
mutex_unlock(&cgroup_root_mutex);
@@ -1727,8 +1709,6 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
mutex_unlock(&inode->i_mutex);
drop_new_super:
deactivate_locked_super(sb);
- drop_modules:
- drop_parsed_module_refcounts(opts.subsys_mask);
out_err:
kfree(opts.release_agent);
kfree(opts.name);
@@ -1746,6 +1726,7 @@ static void cgroup_kill_sb(struct super_block *sb) {
BUG_ON(root->number_of_cgroups != 1);
BUG_ON(!list_empty(&cgrp->children));
+ mutex_lock(&cgrp->dentry->d_inode->i_mutex);
mutex_lock(&cgroup_mutex);
mutex_lock(&cgroup_root_mutex);
@@ -1778,6 +1759,7 @@ static void cgroup_kill_sb(struct super_block *sb) {
mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
+ mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
simple_xattrs_free(&cgrp->xattrs);
@@ -1889,7 +1871,7 @@ EXPORT_SYMBOL_GPL(task_cgroup_path);
struct task_and_cgroup {
struct task_struct *task;
struct cgroup *cgrp;
- struct css_set *cg;
+ struct css_set *cset;
};
struct cgroup_taskset {
@@ -1939,18 +1921,20 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset)
EXPORT_SYMBOL_GPL(cgroup_taskset_next);
/**
- * cgroup_taskset_cur_cgroup - return the matching cgroup for the current task
+ * cgroup_taskset_cur_css - return the matching css for the current task
* @tset: taskset of interest
+ * @subsys_id: the ID of the target subsystem
*
- * Return the cgroup for the current (last returned) task of @tset. This
- * function must be preceded by either cgroup_taskset_first() or
- * cgroup_taskset_next().
+ * Return the css for the current (last returned) task of @tset for
+ * subsystem specified by @subsys_id. This function must be preceded by
+ * either cgroup_taskset_first() or cgroup_taskset_next().
*/
-struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset)
+struct cgroup_subsys_state *cgroup_taskset_cur_css(struct cgroup_taskset *tset,
+ int subsys_id)
{
- return tset->cur_cgrp;
+ return cgroup_css(tset->cur_cgrp, cgroup_subsys[subsys_id]);
}
-EXPORT_SYMBOL_GPL(cgroup_taskset_cur_cgroup);
+EXPORT_SYMBOL_GPL(cgroup_taskset_cur_css);
/**
* cgroup_taskset_size - return the number of tasks in taskset
@@ -2089,8 +2073,10 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
* step 1: check that we can legitimately attach to the cgroup.
*/
for_each_root_subsys(root, ss) {
+ struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
+
if (ss->can_attach) {
- retval = ss->can_attach(cgrp, &tset);
+ retval = ss->can_attach(css, &tset);
if (retval) {
failed_ss = ss;
goto out_cancel_attach;
@@ -2107,8 +2093,8 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
tc = flex_array_get(group, i);
old_cset = task_css_set(tc->task);
- tc->cg = find_css_set(old_cset, cgrp);
- if (!tc->cg) {
+ tc->cset = find_css_set(old_cset, cgrp);
+ if (!tc->cset) {
retval = -ENOMEM;
goto out_put_css_set_refs;
}
@@ -2121,7 +2107,7 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
*/
for (i = 0; i < group_size; i++) {
tc = flex_array_get(group, i);
- cgroup_task_migrate(tc->cgrp, tc->task, tc->cg);
+ cgroup_task_migrate(tc->cgrp, tc->task, tc->cset);
}
/* nothing is sensitive to fork() after this point. */
@@ -2129,8 +2115,10 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
* step 4: do subsystem attach callbacks.
*/
for_each_root_subsys(root, ss) {
+ struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
+
if (ss->attach)
- ss->attach(cgrp, &tset);
+ ss->attach(css, &tset);
}
/*
@@ -2141,18 +2129,20 @@ out_put_css_set_refs:
if (retval) {
for (i = 0; i < group_size; i++) {
tc = flex_array_get(group, i);
- if (!tc->cg)
+ if (!tc->cset)
break;
- put_css_set(tc->cg);
+ put_css_set(tc->cset);
}
}
out_cancel_attach:
if (retval) {
for_each_root_subsys(root, ss) {
+ struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
+
if (ss == failed_ss)
break;
if (ss->cancel_attach)
- ss->cancel_attach(cgrp, &tset);
+ ss->cancel_attach(css, &tset);
}
}
out_free_group_list:
@@ -2253,9 +2243,9 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
mutex_lock(&cgroup_mutex);
for_each_active_root(root) {
- struct cgroup *from_cg = task_cgroup_from_root(from, root);
+ struct cgroup *from_cgrp = task_cgroup_from_root(from, root);
- retval = cgroup_attach_task(from_cg, tsk, false);
+ retval = cgroup_attach_task(from_cgrp, tsk, false);
if (retval)
break;
}
@@ -2265,34 +2255,38 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
}
EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
-static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid)
+static int cgroup_tasks_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 pid)
{
- return attach_task_by_pid(cgrp, pid, false);
+ return attach_task_by_pid(css->cgroup, pid, false);
}
-static int cgroup_procs_write(struct cgroup *cgrp, struct cftype *cft, u64 tgid)
+static int cgroup_procs_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 tgid)
{
- return attach_task_by_pid(cgrp, tgid, true);
+ return attach_task_by_pid(css->cgroup, tgid, true);
}
-static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
+static int cgroup_release_agent_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, const char *buffer)
{
- BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
+ BUILD_BUG_ON(sizeof(css->cgroup->root->release_agent_path) < PATH_MAX);
if (strlen(buffer) >= PATH_MAX)
return -EINVAL;
- if (!cgroup_lock_live_group(cgrp))
+ if (!cgroup_lock_live_group(css->cgroup))
return -ENODEV;
mutex_lock(&cgroup_root_mutex);
- strcpy(cgrp->root->release_agent_path, buffer);
+ strcpy(css->cgroup->root->release_agent_path, buffer);
mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
return 0;
}
-static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft,
- struct seq_file *seq)
+static int cgroup_release_agent_show(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *seq)
{
+ struct cgroup *cgrp = css->cgroup;
+
if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
seq_puts(seq, cgrp->root->release_agent_path);
@@ -2301,20 +2295,20 @@ static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft,
return 0;
}
-static int cgroup_sane_behavior_show(struct cgroup *cgrp, struct cftype *cft,
- struct seq_file *seq)
+static int cgroup_sane_behavior_show(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *seq)
{
- seq_printf(seq, "%d\n", cgroup_sane_behavior(cgrp));
+ seq_printf(seq, "%d\n", cgroup_sane_behavior(css->cgroup));
return 0;
}
/* A buffer size big enough for numbers or short strings */
#define CGROUP_LOCAL_BUFFER_SIZE 64
-static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *unused_ppos)
+static ssize_t cgroup_write_X64(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ const char __user *userbuf, size_t nbytes,
+ loff_t *unused_ppos)
{
char buffer[CGROUP_LOCAL_BUFFER_SIZE];
int retval = 0;
@@ -2332,22 +2326,22 @@ static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft,
u64 val = simple_strtoull(strstrip(buffer), &end, 0);
if (*end)
return -EINVAL;
- retval = cft->write_u64(cgrp, cft, val);
+ retval = cft->write_u64(css, cft, val);
} else {
s64 val = simple_strtoll(strstrip(buffer), &end, 0);
if (*end)
return -EINVAL;
- retval = cft->write_s64(cgrp, cft, val);
+ retval = cft->write_s64(css, cft, val);
}
if (!retval)
retval = nbytes;
return retval;
}
-static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- const char __user *userbuf,
- size_t nbytes, loff_t *unused_ppos)
+static ssize_t cgroup_write_string(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ const char __user *userbuf, size_t nbytes,
+ loff_t *unused_ppos)
{
char local_buffer[CGROUP_LOCAL_BUFFER_SIZE];
int retval = 0;
@@ -2370,7 +2364,7 @@ static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft,
}
buffer[nbytes] = 0; /* nul-terminate */
- retval = cft->write_string(cgrp, cft, strstrip(buffer));
+ retval = cft->write_string(css, cft, strstrip(buffer));
if (!retval)
retval = nbytes;
out:
@@ -2380,65 +2374,60 @@ out:
}
static ssize_t cgroup_file_write(struct file *file, const char __user *buf,
- size_t nbytes, loff_t *ppos)
+ size_t nbytes, loff_t *ppos)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
struct cftype *cft = __d_cft(file->f_dentry);
- struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
+ struct cgroup_subsys_state *css = cfe->css;
- if (cgroup_is_dead(cgrp))
- return -ENODEV;
if (cft->write)
- return cft->write(cgrp, cft, file, buf, nbytes, ppos);
+ return cft->write(css, cft, file, buf, nbytes, ppos);
if (cft->write_u64 || cft->write_s64)
- return cgroup_write_X64(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_write_X64(css, cft, file, buf, nbytes, ppos);
if (cft->write_string)
- return cgroup_write_string(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_write_string(css, cft, file, buf, nbytes, ppos);
if (cft->trigger) {
- int ret = cft->trigger(cgrp, (unsigned int)cft->private);
+ int ret = cft->trigger(css, (unsigned int)cft->private);
return ret ? ret : nbytes;
}
return -EINVAL;
}
-static ssize_t cgroup_read_u64(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- char __user *buf, size_t nbytes,
- loff_t *ppos)
+static ssize_t cgroup_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ char __user *buf, size_t nbytes, loff_t *ppos)
{
char tmp[CGROUP_LOCAL_BUFFER_SIZE];
- u64 val = cft->read_u64(cgrp, cft);
+ u64 val = cft->read_u64(css, cft);
int len = sprintf(tmp, "%llu\n", (unsigned long long) val);
return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
}
-static ssize_t cgroup_read_s64(struct cgroup *cgrp, struct cftype *cft,
- struct file *file,
- char __user *buf, size_t nbytes,
- loff_t *ppos)
+static ssize_t cgroup_read_s64(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ char __user *buf, size_t nbytes, loff_t *ppos)
{
char tmp[CGROUP_LOCAL_BUFFER_SIZE];
- s64 val = cft->read_s64(cgrp, cft);
+ s64 val = cft->read_s64(css, cft);
int len = sprintf(tmp, "%lld\n", (long long) val);
return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
}
static ssize_t cgroup_file_read(struct file *file, char __user *buf,
- size_t nbytes, loff_t *ppos)
+ size_t nbytes, loff_t *ppos)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
struct cftype *cft = __d_cft(file->f_dentry);
- struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
-
- if (cgroup_is_dead(cgrp))
- return -ENODEV;
+ struct cgroup_subsys_state *css = cfe->css;
if (cft->read)
- return cft->read(cgrp, cft, file, buf, nbytes, ppos);
+ return cft->read(css, cft, file, buf, nbytes, ppos);
if (cft->read_u64)
- return cgroup_read_u64(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_read_u64(css, cft, file, buf, nbytes, ppos);
if (cft->read_s64)
- return cgroup_read_s64(cgrp, cft, file, buf, nbytes, ppos);
+ return cgroup_read_s64(css, cft, file, buf, nbytes, ppos);
return -EINVAL;
}
@@ -2447,11 +2436,6 @@ static ssize_t cgroup_file_read(struct file *file, char __user *buf,
* supports string->u64 maps, but can be extended in future.
*/
-struct cgroup_seqfile_state {
- struct cftype *cft;
- struct cgroup *cgroup;
-};
-
static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value)
{
struct seq_file *sf = cb->state;
@@ -2460,69 +2444,86 @@ static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value)
static int cgroup_seqfile_show(struct seq_file *m, void *arg)
{
- struct cgroup_seqfile_state *state = m->private;
- struct cftype *cft = state->cft;
+ struct cfent *cfe = m->private;
+ struct cftype *cft = cfe->type;
+ struct cgroup_subsys_state *css = cfe->css;
+
if (cft->read_map) {
struct cgroup_map_cb cb = {
.fill = cgroup_map_add,
.state = m,
};
- return cft->read_map(state->cgroup, cft, &cb);
+ return cft->read_map(css, cft, &cb);
}
- return cft->read_seq_string(state->cgroup, cft, m);
-}
-
-static int cgroup_seqfile_release(struct inode *inode, struct file *file)
-{
- struct seq_file *seq = file->private_data;
- kfree(seq->private);
- return single_release(inode, file);
+ return cft->read_seq_string(css, cft, m);
}
static const struct file_operations cgroup_seqfile_operations = {
.read = seq_read,
.write = cgroup_file_write,
.llseek = seq_lseek,
- .release = cgroup_seqfile_release,
+ .release = single_release,
};
static int cgroup_file_open(struct inode *inode, struct file *file)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
+ struct cftype *cft = __d_cft(file->f_dentry);
+ struct cgroup *cgrp = __d_cgrp(cfe->dentry->d_parent);
+ struct cgroup_subsys_state *css;
int err;
- struct cftype *cft;
err = generic_file_open(inode, file);
if (err)
return err;
- cft = __d_cft(file->f_dentry);
- if (cft->read_map || cft->read_seq_string) {
- struct cgroup_seqfile_state *state;
+ /*
+ * If the file belongs to a subsystem, pin the css. Will be
+ * unpinned either on open failure or release. This ensures that
+ * @css stays alive for all file operations.
+ */
+ rcu_read_lock();
+ css = cgroup_css(cgrp, cft->ss);
+ if (cft->ss && !css_tryget(css))
+ css = NULL;
+ rcu_read_unlock();
- state = kzalloc(sizeof(*state), GFP_USER);
- if (!state)
- return -ENOMEM;
+ if (!css)
+ return -ENODEV;
- state->cft = cft;
- state->cgroup = __d_cgrp(file->f_dentry->d_parent);
+ /*
+ * @cfe->css is used by read/write/close to determine the
+ * associated css. @file->private_data would be a better place but
+ * that's already used by seqfile. Multiple accessors may use it
+ * simultaneously which is okay as the association never changes.
+ */
+ WARN_ON_ONCE(cfe->css && cfe->css != css);
+ cfe->css = css;
+
+ if (cft->read_map || cft->read_seq_string) {
file->f_op = &cgroup_seqfile_operations;
- err = single_open(file, cgroup_seqfile_show, state);
- if (err < 0)
- kfree(state);
- } else if (cft->open)
+ err = single_open(file, cgroup_seqfile_show, cfe);
+ } else if (cft->open) {
err = cft->open(inode, file);
- else
- err = 0;
+ }
+ if (css->ss && err)
+ css_put(css);
return err;
}
static int cgroup_file_release(struct inode *inode, struct file *file)
{
+ struct cfent *cfe = __d_cfe(file->f_dentry);
struct cftype *cft = __d_cft(file->f_dentry);
+ struct cgroup_subsys_state *css = cfe->css;
+ int ret = 0;
+
if (cft->release)
- return cft->release(inode, file);
- return 0;
+ ret = cft->release(inode, file);
+ if (css->ss)
+ css_put(css);
+ return ret;
}
/*
@@ -2736,8 +2737,7 @@ static umode_t cgroup_file_mode(const struct cftype *cft)
return mode;
}
-static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
- struct cftype *cft)
+static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft)
{
struct dentry *dir = cgrp->dentry;
struct cgroup *parent = __d_cgrp(dir);
@@ -2747,8 +2747,9 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
umode_t mode;
char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 };
- if (subsys && !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) {
- strcpy(name, subsys->name);
+ if (cft->ss && !(cft->flags & CFTYPE_NO_PREFIX) &&
+ !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) {
+ strcpy(name, cft->ss->name);
strcat(name, ".");
}
strcat(name, cft->name);
@@ -2782,11 +2783,25 @@ out:
return error;
}
-static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
- struct cftype cfts[], bool is_add)
+/**
+ * cgroup_addrm_files - add or remove files to a cgroup directory
+ * @cgrp: the target cgroup
+ * @cfts: array of cftypes to be added
+ * @is_add: whether to add or remove
+ *
+ * Depending on @is_add, add or remove files defined by @cfts on @cgrp.
+ * For removals, this function never fails. If addition fails, this
+ * function doesn't remove files already added. The caller is responsible
+ * for cleaning up.
+ */
+static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],
+ bool is_add)
{
struct cftype *cft;
- int err, ret = 0;
+ int ret;
+
+ lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex);
+ lockdep_assert_held(&cgroup_mutex);
for (cft = cfts; cft->name[0] != '\0'; cft++) {
/* does cft->flags tell us to skip this file on @cgrp? */
@@ -2798,16 +2813,17 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
continue;
if (is_add) {
- err = cgroup_add_file(cgrp, subsys, cft);
- if (err)
+ ret = cgroup_add_file(cgrp, cft);
+ if (ret) {
pr_warn("cgroup_addrm_files: failed to add %s, err=%d\n",
- cft->name, err);
- ret = err;
+ cft->name, ret);
+ return ret;
+ }
} else {
cgroup_rm_file(cgrp, cft);
}
}
- return ret;
+ return 0;
}
static void cgroup_cfts_prepare(void)
@@ -2816,28 +2832,30 @@ static void cgroup_cfts_prepare(void)
/*
* Thanks to the entanglement with vfs inode locking, we can't walk
* the existing cgroups under cgroup_mutex and create files.
- * Instead, we use cgroup_for_each_descendant_pre() and drop RCU
- * read lock before calling cgroup_addrm_files().
+ * Instead, we use css_for_each_descendant_pre() and drop RCU read
+ * lock before calling cgroup_addrm_files().
*/
mutex_lock(&cgroup_mutex);
}
-static void cgroup_cfts_commit(struct cgroup_subsys *ss,
- struct cftype *cfts, bool is_add)
+static int cgroup_cfts_commit(struct cftype *cfts, bool is_add)
__releases(&cgroup_mutex)
{
LIST_HEAD(pending);
- struct cgroup *cgrp, *root = &ss->root->top_cgroup;
+ struct cgroup_subsys *ss = cfts[0].ss;
+ struct cgroup *root = &ss->root->top_cgroup;
struct super_block *sb = ss->root->sb;
struct dentry *prev = NULL;
struct inode *inode;
+ struct cgroup_subsys_state *css;
u64 update_before;
+ int ret = 0;
/* %NULL @cfts indicates abort and don't bother if @ss isn't attached */
if (!cfts || ss->root == &cgroup_dummy_root ||
!atomic_inc_not_zero(&sb->s_active)) {
mutex_unlock(&cgroup_mutex);
- return;
+ return 0;
}
/*
@@ -2849,17 +2867,11 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss,
mutex_unlock(&cgroup_mutex);
- /* @root always needs to be updated */
- inode = root->dentry->d_inode;
- mutex_lock(&inode->i_mutex);
- mutex_lock(&cgroup_mutex);
- cgroup_addrm_files(root, ss, cfts, is_add);
- mutex_unlock(&cgroup_mutex);
- mutex_unlock(&inode->i_mutex);
-
/* add/rm files for all cgroups created before */
rcu_read_lock();
- cgroup_for_each_descendant_pre(cgrp, root) {
+ css_for_each_descendant_pre(css, cgroup_css(root, ss)) {
+ struct cgroup *cgrp = css->cgroup;
+
if (cgroup_is_dead(cgrp))
continue;
@@ -2873,15 +2885,18 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss,
mutex_lock(&inode->i_mutex);
mutex_lock(&cgroup_mutex);
if (cgrp->serial_nr < update_before && !cgroup_is_dead(cgrp))
- cgroup_addrm_files(cgrp, ss, cfts, is_add);
+ ret = cgroup_addrm_files(cgrp, cfts, is_add);
mutex_unlock(&cgroup_mutex);
mutex_unlock(&inode->i_mutex);
rcu_read_lock();
+ if (ret)
+ break;
}
rcu_read_unlock();
dput(prev);
deactivate_super(sb);
+ return ret;
}
/**
@@ -2901,49 +2916,56 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss,
int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
{
struct cftype_set *set;
+ struct cftype *cft;
+ int ret;
set = kzalloc(sizeof(*set), GFP_KERNEL);
if (!set)
return -ENOMEM;
+ for (cft = cfts; cft->name[0] != '\0'; cft++)
+ cft->ss = ss;
+
cgroup_cfts_prepare();
set->cfts = cfts;
list_add_tail(&set->node, &ss->cftsets);
- cgroup_cfts_commit(ss, cfts, true);
-
- return 0;
+ ret = cgroup_cfts_commit(cfts, true);
+ if (ret)
+ cgroup_rm_cftypes(cfts);
+ return ret;
}
EXPORT_SYMBOL_GPL(cgroup_add_cftypes);
/**
* cgroup_rm_cftypes - remove an array of cftypes from a subsystem
- * @ss: target cgroup subsystem
* @cfts: zero-length name terminated array of cftypes
*
- * Unregister @cfts from @ss. Files described by @cfts are removed from
- * all existing cgroups to which @ss is attached and all future cgroups
- * won't have them either. This function can be called anytime whether @ss
- * is attached or not.
+ * Unregister @cfts. Files described by @cfts are removed from all
+ * existing cgroups and all future cgroups won't have them either. This
+ * function can be called anytime whether @cfts' subsys is attached or not.
*
* Returns 0 on successful unregistration, -ENOENT if @cfts is not
- * registered with @ss.
+ * registered.
*/
-int cgroup_rm_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
+int cgroup_rm_cftypes(struct cftype *cfts)
{
struct cftype_set *set;
+ if (!cfts || !cfts[0].ss)
+ return -ENOENT;
+
cgroup_cfts_prepare();
- list_for_each_entry(set, &ss->cftsets, node) {
+ list_for_each_entry(set, &cfts[0].ss->cftsets, node) {
if (set->cfts == cfts) {
list_del(&set->node);
kfree(set);
- cgroup_cfts_commit(ss, cfts, false);
+ cgroup_cfts_commit(cfts, false);
return 0;
}
}
- cgroup_cfts_commit(ss, NULL, false);
+ cgroup_cfts_commit(NULL, false);
return -ENOENT;
}
@@ -2966,34 +2988,10 @@ int cgroup_task_count(const struct cgroup *cgrp)
}
/*
- * Advance a list_head iterator. The iterator should be positioned at
- * the start of a css_set
- */
-static void cgroup_advance_iter(struct cgroup *cgrp, struct cgroup_iter *it)
-{
- struct list_head *l = it->cset_link;
- struct cgrp_cset_link *link;
- struct css_set *cset;
-
- /* Advance to the next non-empty css_set */
- do {
- l = l->next;
- if (l == &cgrp->cset_links) {
- it->cset_link = NULL;
- return;
- }
- link = list_entry(l, struct cgrp_cset_link, cset_link);
- cset = link->cset;
- } while (list_empty(&cset->tasks));
- it->cset_link = l;
- it->task = cset->tasks.next;
-}
-
-/*
- * To reduce the fork() overhead for systems that are not actually
- * using their cgroups capability, we don't maintain the lists running
- * through each css_set to its tasks until we see the list actually
- * used - in other words after the first call to cgroup_iter_start().
+ * To reduce the fork() overhead for systems that are not actually using
+ * their cgroups capability, we don't maintain the lists running through
+ * each css_set to its tasks until we see the list actually used - in other
+ * words after the first call to css_task_iter_start().
*/
static void cgroup_enable_task_cg_lists(void)
{
@@ -3024,16 +3022,21 @@ static void cgroup_enable_task_cg_lists(void)
}
/**
- * cgroup_next_sibling - find the next sibling of a given cgroup
- * @pos: the current cgroup
+ * css_next_child - find the next child of a given css
+ * @pos_css: the current position (%NULL to initiate traversal)
+ * @parent_css: css whose children to walk
*
- * This function returns the next sibling of @pos and should be called
- * under RCU read lock. The only requirement is that @pos is accessible.
- * The next sibling is guaranteed to be returned regardless of @pos's
- * state.
+ * This function returns the next child of @parent_css and should be called
+ * under RCU read lock. The only requirement is that @parent_css and
+ * @pos_css are accessible. The next sibling is guaranteed to be returned
+ * regardless of their states.
*/
-struct cgroup *cgroup_next_sibling(struct cgroup *pos)
+struct cgroup_subsys_state *
+css_next_child(struct cgroup_subsys_state *pos_css,
+ struct cgroup_subsys_state *parent_css)
{
+ struct cgroup *pos = pos_css ? pos_css->cgroup : NULL;
+ struct cgroup *cgrp = parent_css->cgroup;
struct cgroup *next;
WARN_ON_ONCE(!rcu_read_lock_held());
@@ -3048,78 +3051,81 @@ struct cgroup *cgroup_next_sibling(struct cgroup *pos)
* safe to dereference from this RCU critical section. If
* ->sibling.next is inaccessible, cgroup_is_dead() is guaranteed
* to be visible as %true here.
+ *
+ * If @pos is dead, its next pointer can't be dereferenced;
+ * however, as each cgroup is given a monotonically increasing
+ * unique serial number and always appended to the sibling list,
+ * the next one can be found by walking the parent's children until
+ * we see a cgroup with higher serial number than @pos's. While
+ * this path can be slower, it's taken only when either the current
+ * cgroup is removed or iteration and removal race.
*/
- if (likely(!cgroup_is_dead(pos))) {
+ if (!pos) {
+ next = list_entry_rcu(cgrp->children.next, struct cgroup, sibling);
+ } else if (likely(!cgroup_is_dead(pos))) {
next = list_entry_rcu(pos->sibling.next, struct cgroup, sibling);
- if (&next->sibling != &pos->parent->children)
- return next;
- return NULL;
+ } else {
+ list_for_each_entry_rcu(next, &cgrp->children, sibling)
+ if (next->serial_nr > pos->serial_nr)
+ break;
}
- /*
- * Can't dereference the next pointer. Each cgroup is given a
- * monotonically increasing unique serial number and always
- * appended to the sibling list, so the next one can be found by
- * walking the parent's children until we see a cgroup with higher
- * serial number than @pos's.
- *
- * While this path can be slow, it's taken only when either the
- * current cgroup is removed or iteration and removal race.
- */
- list_for_each_entry_rcu(next, &pos->parent->children, sibling)
- if (next->serial_nr > pos->serial_nr)
- return next;
- return NULL;
+ if (&next->sibling == &cgrp->children)
+ return NULL;
+
+ return cgroup_css(next, parent_css->ss);
}
-EXPORT_SYMBOL_GPL(cgroup_next_sibling);
+EXPORT_SYMBOL_GPL(css_next_child);
/**
- * cgroup_next_descendant_pre - find the next descendant for pre-order walk
+ * css_next_descendant_pre - find the next descendant for pre-order walk
* @pos: the current position (%NULL to initiate traversal)
- * @cgroup: cgroup whose descendants to walk
+ * @root: css whose descendants to walk
*
- * To be used by cgroup_for_each_descendant_pre(). Find the next
- * descendant to visit for pre-order traversal of @cgroup's descendants.
+ * To be used by css_for_each_descendant_pre(). Find the next descendant
+ * to visit for pre-order traversal of @root's descendants. @root is
+ * included in the iteration and the first node to be visited.
*
* While this function requires RCU read locking, it doesn't require the
* whole traversal to be contained in a single RCU critical section. This
* function will return the correct next descendant as long as both @pos
- * and @cgroup are accessible and @pos is a descendant of @cgroup.
+ * and @root are accessible and @pos is a descendant of @root.
*/
-struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos,
- struct cgroup *cgroup)
+struct cgroup_subsys_state *
+css_next_descendant_pre(struct cgroup_subsys_state *pos,
+ struct cgroup_subsys_state *root)
{
- struct cgroup *next;
+ struct cgroup_subsys_state *next;
WARN_ON_ONCE(!rcu_read_lock_held());
- /* if first iteration, pretend we just visited @cgroup */
+ /* if first iteration, visit @root */
if (!pos)
- pos = cgroup;
+ return root;
/* visit the first child if exists */
- next = list_first_or_null_rcu(&pos->children, struct cgroup, sibling);
+ next = css_next_child(NULL, pos);
if (next)
return next;
/* no child, visit my or the closest ancestor's next sibling */
- while (pos != cgroup) {
- next = cgroup_next_sibling(pos);
+ while (pos != root) {
+ next = css_next_child(pos, css_parent(pos));
if (next)
return next;
- pos = pos->parent;
+ pos = css_parent(pos);
}
return NULL;
}
-EXPORT_SYMBOL_GPL(cgroup_next_descendant_pre);
+EXPORT_SYMBOL_GPL(css_next_descendant_pre);
/**
- * cgroup_rightmost_descendant - return the rightmost descendant of a cgroup
- * @pos: cgroup of interest
+ * css_rightmost_descendant - return the rightmost descendant of a css
+ * @pos: css of interest
*
- * Return the rightmost descendant of @pos. If there's no descendant,
- * @pos is returned. This can be used during pre-order traversal to skip
+ * Return the rightmost descendant of @pos. If there's no descendant, @pos
+ * is returned. This can be used during pre-order traversal to skip
* subtree of @pos.
*
* While this function requires RCU read locking, it doesn't require the
@@ -3127,9 +3133,10 @@ EXPORT_SYMBOL_GPL(cgroup_next_descendant_pre);
* function will return the correct rightmost descendant as long as @pos is
* accessible.
*/
-struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos)
+struct cgroup_subsys_state *
+css_rightmost_descendant(struct cgroup_subsys_state *pos)
{
- struct cgroup *last, *tmp;
+ struct cgroup_subsys_state *last, *tmp;
WARN_ON_ONCE(!rcu_read_lock_held());
@@ -3137,82 +3144,138 @@ struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos)
last = pos;
/* ->prev isn't RCU safe, walk ->next till the end */
pos = NULL;
- list_for_each_entry_rcu(tmp, &last->children, sibling)
+ css_for_each_child(tmp, last)
pos = tmp;
} while (pos);
return last;
}
-EXPORT_SYMBOL_GPL(cgroup_rightmost_descendant);
+EXPORT_SYMBOL_GPL(css_rightmost_descendant);
-static struct cgroup *cgroup_leftmost_descendant(struct cgroup *pos)
+static struct cgroup_subsys_state *
+css_leftmost_descendant(struct cgroup_subsys_state *pos)
{
- struct cgroup *last;
+ struct cgroup_subsys_state *last;
do {
last = pos;
- pos = list_first_or_null_rcu(&pos->children, struct cgroup,
- sibling);
+ pos = css_next_child(NULL, pos);
} while (pos);
return last;
}
/**
- * cgroup_next_descendant_post - find the next descendant for post-order walk
+ * css_next_descendant_post - find the next descendant for post-order walk
* @pos: the current position (%NULL to initiate traversal)
- * @cgroup: cgroup whose descendants to walk
+ * @root: css whose descendants to walk
*
- * To be used by cgroup_for_each_descendant_post(). Find the next
- * descendant to visit for post-order traversal of @cgroup's descendants.
+ * To be used by css_for_each_descendant_post(). Find the next descendant
+ * to visit for post-order traversal of @root's descendants. @root is
+ * included in the iteration and the last node to be visited.
*
* While this function requires RCU read locking, it doesn't require the
* whole traversal to be contained in a single RCU critical section. This
* function will return the correct next descendant as long as both @pos
* and @cgroup are accessible and @pos is a descendant of @cgroup.
*/
-struct cgroup *cgroup_next_descendant_post(struct cgroup *pos,
- struct cgroup *cgroup)
+struct cgroup_subsys_state *
+css_next_descendant_post(struct cgroup_subsys_state *pos,
+ struct cgroup_subsys_state *root)
{
- struct cgroup *next;
+ struct cgroup_subsys_state *next;
WARN_ON_ONCE(!rcu_read_lock_held());
/* if first iteration, visit the leftmost descendant */
if (!pos) {
- next = cgroup_leftmost_descendant(cgroup);
- return next != cgroup ? next : NULL;
+ next = css_leftmost_descendant(root);
+ return next != root ? next : NULL;
}
+ /* if we visited @root, we're done */
+ if (pos == root)
+ return NULL;
+
/* if there's an unvisited sibling, visit its leftmost descendant */
- next = cgroup_next_sibling(pos);
+ next = css_next_child(pos, css_parent(pos));
if (next)
- return cgroup_leftmost_descendant(next);
+ return css_leftmost_descendant(next);
/* no sibling left, visit parent */
- next = pos->parent;
- return next != cgroup ? next : NULL;
+ return css_parent(pos);
+}
+EXPORT_SYMBOL_GPL(css_next_descendant_post);
+
+/**
+ * css_advance_task_iter - advance a task itererator to the next css_set
+ * @it: the iterator to advance
+ *
+ * Advance @it to the next css_set to walk.
+ */
+static void css_advance_task_iter(struct css_task_iter *it)
+{
+ struct list_head *l = it->cset_link;
+ struct cgrp_cset_link *link;
+ struct css_set *cset;
+
+ /* Advance to the next non-empty css_set */
+ do {
+ l = l->next;
+ if (l == &it->origin_css->cgroup->cset_links) {
+ it->cset_link = NULL;
+ return;
+ }
+ link = list_entry(l, struct cgrp_cset_link, cset_link);
+ cset = link->cset;
+ } while (list_empty(&cset->tasks));
+ it->cset_link = l;
+ it->task = cset->tasks.next;
}
-EXPORT_SYMBOL_GPL(cgroup_next_descendant_post);
-void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it)
+/**
+ * css_task_iter_start - initiate task iteration
+ * @css: the css to walk tasks of
+ * @it: the task iterator to use
+ *
+ * Initiate iteration through the tasks of @css. The caller can call
+ * css_task_iter_next() to walk through the tasks until the function
+ * returns NULL. On completion of iteration, css_task_iter_end() must be
+ * called.
+ *
+ * Note that this function acquires a lock which is released when the
+ * iteration finishes. The caller can't sleep while iteration is in
+ * progress.
+ */
+void css_task_iter_start(struct cgroup_subsys_state *css,
+ struct css_task_iter *it)
__acquires(css_set_lock)
{
/*
- * The first time anyone tries to iterate across a cgroup,
- * we need to enable the list linking each css_set to its
- * tasks, and fix up all existing tasks.
+ * The first time anyone tries to iterate across a css, we need to
+ * enable the list linking each css_set to its tasks, and fix up
+ * all existing tasks.
*/
if (!use_task_css_set_links)
cgroup_enable_task_cg_lists();
read_lock(&css_set_lock);
- it->cset_link = &cgrp->cset_links;
- cgroup_advance_iter(cgrp, it);
+
+ it->origin_css = css;
+ it->cset_link = &css->cgroup->cset_links;
+
+ css_advance_task_iter(it);
}
-struct task_struct *cgroup_iter_next(struct cgroup *cgrp,
- struct cgroup_iter *it)
+/**
+ * css_task_iter_next - return the next task for the iterator
+ * @it: the task iterator being iterated
+ *
+ * The "next" function for task iteration. @it should have been
+ * initialized via css_task_iter_start(). Returns NULL when the iteration
+ * reaches the end.
+ */
+struct task_struct *css_task_iter_next(struct css_task_iter *it)
{
struct task_struct *res;
struct list_head *l = it->task;
@@ -3226,16 +3289,24 @@ struct task_struct *cgroup_iter_next(struct cgroup *cgrp,
l = l->next;
link = list_entry(it->cset_link, struct cgrp_cset_link, cset_link);
if (l == &link->cset->tasks) {
- /* We reached the end of this task list - move on to
- * the next cg_cgroup_link */
- cgroup_advance_iter(cgrp, it);
+ /*
+ * We reached the end of this task list - move on to the
+ * next cgrp_cset_link.
+ */
+ css_advance_task_iter(it);
} else {
it->task = l;
}
return res;
}
-void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it)
+/**
+ * css_task_iter_end - finish task iteration
+ * @it: the task iterator to finish
+ *
+ * Finish task iteration started by css_task_iter_start().
+ */
+void css_task_iter_end(struct css_task_iter *it)
__releases(css_set_lock)
{
read_unlock(&css_set_lock);
@@ -3276,46 +3347,49 @@ static inline int started_after(void *p1, void *p2)
}
/**
- * cgroup_scan_tasks - iterate though all the tasks in a cgroup
- * @scan: struct cgroup_scanner containing arguments for the scan
+ * css_scan_tasks - iterate though all the tasks in a css
+ * @css: the css to iterate tasks of
+ * @test: optional test callback
+ * @process: process callback
+ * @data: data passed to @test and @process
+ * @heap: optional pre-allocated heap used for task iteration
+ *
+ * Iterate through all the tasks in @css, calling @test for each, and if it
+ * returns %true, call @process for it also.
+ *
+ * @test may be NULL, meaning always true (select all tasks), which
+ * effectively duplicates css_task_iter_{start,next,end}() but does not
+ * lock css_set_lock for the call to @process.
*
- * Arguments include pointers to callback functions test_task() and
- * process_task().
- * Iterate through all the tasks in a cgroup, calling test_task() for each,
- * and if it returns true, call process_task() for it also.
- * The test_task pointer may be NULL, meaning always true (select all tasks).
- * Effectively duplicates cgroup_iter_{start,next,end}()
- * but does not lock css_set_lock for the call to process_task().
- * The struct cgroup_scanner may be embedded in any structure of the caller's
- * creation.
- * It is guaranteed that process_task() will act on every task that
- * is a member of the cgroup for the duration of this call. This
- * function may or may not call process_task() for tasks that exit
- * or move to a different cgroup during the call, or are forked or
- * move into the cgroup during the call.
+ * It is guaranteed that @process will act on every task that is a member
+ * of @css for the duration of this call. This function may or may not
+ * call @process for tasks that exit or move to a different css during the
+ * call, or are forked or move into the css during the call.
*
- * Note that test_task() may be called with locks held, and may in some
- * situations be called multiple times for the same task, so it should
- * be cheap.
- * If the heap pointer in the struct cgroup_scanner is non-NULL, a heap has been
- * pre-allocated and will be used for heap operations (and its "gt" member will
- * be overwritten), else a temporary heap will be used (allocation of which
- * may cause this function to fail).
+ * Note that @test may be called with locks held, and may in some
+ * situations be called multiple times for the same task, so it should be
+ * cheap.
+ *
+ * If @heap is non-NULL, a heap has been pre-allocated and will be used for
+ * heap operations (and its "gt" member will be overwritten), else a
+ * temporary heap will be used (allocation of which may cause this function
+ * to fail).
*/
-int cgroup_scan_tasks(struct cgroup_scanner *scan)
+int css_scan_tasks(struct cgroup_subsys_state *css,
+ bool (*test)(struct task_struct *, void *),
+ void (*process)(struct task_struct *, void *),
+ void *data, struct ptr_heap *heap)
{
int retval, i;
- struct cgroup_iter it;
+ struct css_task_iter it;
struct task_struct *p, *dropped;
/* Never dereference latest_task, since it's not refcounted */
struct task_struct *latest_task = NULL;
struct ptr_heap tmp_heap;
- struct ptr_heap *heap;
struct timespec latest_time = { 0, 0 };
- if (scan->heap) {
+ if (heap) {
/* The caller supplied our heap and pre-allocated its memory */
- heap = scan->heap;
heap->gt = &started_after;
} else {
/* We need to allocate our own heap memory */
@@ -3328,25 +3402,24 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
again:
/*
- * Scan tasks in the cgroup, using the scanner's "test_task" callback
- * to determine which are of interest, and using the scanner's
- * "process_task" callback to process any of them that need an update.
- * Since we don't want to hold any locks during the task updates,
- * gather tasks to be processed in a heap structure.
- * The heap is sorted by descending task start time.
- * If the statically-sized heap fills up, we overflow tasks that
- * started later, and in future iterations only consider tasks that
- * started after the latest task in the previous pass. This
+ * Scan tasks in the css, using the @test callback to determine
+ * which are of interest, and invoking @process callback on the
+ * ones which need an update. Since we don't want to hold any
+ * locks during the task updates, gather tasks to be processed in a
+ * heap structure. The heap is sorted by descending task start
+ * time. If the statically-sized heap fills up, we overflow tasks
+ * that started later, and in future iterations only consider tasks
+ * that started after the latest task in the previous pass. This
* guarantees forward progress and that we don't miss any tasks.
*/
heap->size = 0;
- cgroup_iter_start(scan->cg, &it);
- while ((p = cgroup_iter_next(scan->cg, &it))) {
+ css_task_iter_start(css, &it);
+ while ((p = css_task_iter_next(&it))) {
/*
* Only affect tasks that qualify per the caller's callback,
* if he provided one
*/
- if (scan->test_task && !scan->test_task(p, scan))
+ if (test && !test(p, data))
continue;
/*
* Only process tasks that started after the last task
@@ -3374,7 +3447,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
* the heap and wasn't inserted
*/
}
- cgroup_iter_end(scan->cg, &it);
+ css_task_iter_end(&it);
if (heap->size) {
for (i = 0; i < heap->size; i++) {
@@ -3384,7 +3457,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
latest_task = q;
}
/* Process the task per the caller's callback */
- scan->process_task(q, scan);
+ process(q, data);
put_task_struct(q);
}
/*
@@ -3401,10 +3474,9 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan)
return 0;
}
-static void cgroup_transfer_one_task(struct task_struct *task,
- struct cgroup_scanner *scan)
+static void cgroup_transfer_one_task(struct task_struct *task, void *data)
{
- struct cgroup *new_cgroup = scan->data;
+ struct cgroup *new_cgroup = data;
mutex_lock(&cgroup_mutex);
cgroup_attach_task(new_cgroup, task, false);
@@ -3418,15 +3490,8 @@ static void cgroup_transfer_one_task(struct task_struct *task,
*/
int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
{
- struct cgroup_scanner scan;
-
- scan.cg = from;
- scan.test_task = NULL; /* select all tasks in cgroup */
- scan.process_task = cgroup_transfer_one_task;
- scan.heap = NULL;
- scan.data = to;
-
- return cgroup_scan_tasks(&scan);
+ return css_scan_tasks(&from->dummy_css, NULL, cgroup_transfer_one_task,
+ to, NULL);
}
/*
@@ -3468,7 +3533,7 @@ struct cgroup_pidlist {
/* pointer to the cgroup we belong to, for list removal purposes */
struct cgroup *owner;
/* protects the other fields */
- struct rw_semaphore mutex;
+ struct rw_semaphore rwsem;
};
/*
@@ -3541,7 +3606,7 @@ static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
struct pid_namespace *ns = task_active_pid_ns(current);
/*
- * We can't drop the pidlist_mutex before taking the l->mutex in case
+ * We can't drop the pidlist_mutex before taking the l->rwsem in case
* the last ref-holder is trying to remove l from the list at the same
* time. Holding the pidlist_mutex precludes somebody taking whichever
* list we find out from under us - compare release_pid_array().
@@ -3550,7 +3615,7 @@ static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
list_for_each_entry(l, &cgrp->pidlists, links) {
if (l->key.type == type && l->key.ns == ns) {
/* make sure l doesn't vanish out from under us */
- down_write(&l->mutex);
+ down_write(&l->rwsem);
mutex_unlock(&cgrp->pidlist_mutex);
return l;
}
@@ -3561,8 +3626,8 @@ static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
mutex_unlock(&cgrp->pidlist_mutex);
return l;
}
- init_rwsem(&l->mutex);
- down_write(&l->mutex);
+ init_rwsem(&l->rwsem);
+ down_write(&l->rwsem);
l->key.type = type;
l->key.ns = get_pid_ns(ns);
l->owner = cgrp;
@@ -3580,7 +3645,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
pid_t *array;
int length;
int pid, n = 0; /* used for populating the array */
- struct cgroup_iter it;
+ struct css_task_iter it;
struct task_struct *tsk;
struct cgroup_pidlist *l;
@@ -3595,8 +3660,8 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
if (!array)
return -ENOMEM;
/* now, populate the array */
- cgroup_iter_start(cgrp, &it);
- while ((tsk = cgroup_iter_next(cgrp, &it))) {
+ css_task_iter_start(&cgrp->dummy_css, &it);
+ while ((tsk = css_task_iter_next(&it))) {
if (unlikely(n == length))
break;
/* get tgid or pid for procs or tasks file respectively */
@@ -3607,7 +3672,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
if (pid > 0) /* make sure to only use valid results */
array[n++] = pid;
}
- cgroup_iter_end(cgrp, &it);
+ css_task_iter_end(&it);
length = n;
/* now sort & (if procs) strip out duplicates */
sort(array, length, sizeof(pid_t), cmppid, NULL);
@@ -3623,7 +3688,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
l->list = array;
l->length = length;
l->use_count++;
- up_write(&l->mutex);
+ up_write(&l->rwsem);
*lp = l;
return 0;
}
@@ -3641,7 +3706,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
{
int ret = -EINVAL;
struct cgroup *cgrp;
- struct cgroup_iter it;
+ struct css_task_iter it;
struct task_struct *tsk;
/*
@@ -3655,8 +3720,8 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
ret = 0;
cgrp = dentry->d_fsdata;
- cgroup_iter_start(cgrp, &it);
- while ((tsk = cgroup_iter_next(cgrp, &it))) {
+ css_task_iter_start(&cgrp->dummy_css, &it);
+ while ((tsk = css_task_iter_next(&it))) {
switch (tsk->state) {
case TASK_RUNNING:
stats->nr_running++;
@@ -3676,7 +3741,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
break;
}
}
- cgroup_iter_end(cgrp, &it);
+ css_task_iter_end(&it);
err:
return ret;
@@ -3701,7 +3766,7 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
int index = 0, pid = *pos;
int *iter;
- down_read(&l->mutex);
+ down_read(&l->rwsem);
if (pid) {
int end = l->length;
@@ -3728,7 +3793,7 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
static void cgroup_pidlist_stop(struct seq_file *s, void *v)
{
struct cgroup_pidlist *l = s->private;
- up_read(&l->mutex);
+ up_read(&l->rwsem);
}
static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
@@ -3774,7 +3839,7 @@ static void cgroup_release_pid_array(struct cgroup_pidlist *l)
* pidlist_mutex, we have to take pidlist_mutex first.
*/
mutex_lock(&l->owner->pidlist_mutex);
- down_write(&l->mutex);
+ down_write(&l->rwsem);
BUG_ON(!l->use_count);
if (!--l->use_count) {
/* we're the last user if refcount is 0; remove and free */
@@ -3782,12 +3847,12 @@ static void cgroup_release_pid_array(struct cgroup_pidlist *l)
mutex_unlock(&l->owner->pidlist_mutex);
pidlist_free(l->list);
put_pid_ns(l->key.ns);
- up_write(&l->mutex);
+ up_write(&l->rwsem);
kfree(l);
return;
}
mutex_unlock(&l->owner->pidlist_mutex);
- up_write(&l->mutex);
+ up_write(&l->rwsem);
}
static int cgroup_pidlist_release(struct inode *inode, struct file *file)
@@ -3851,21 +3916,20 @@ static int cgroup_procs_open(struct inode *unused, struct file *file)
return cgroup_pidlist_open(file, CGROUP_FILE_PROCS);
}
-static u64 cgroup_read_notify_on_release(struct cgroup *cgrp,
- struct cftype *cft)
+static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return notify_on_release(cgrp);
+ return notify_on_release(css->cgroup);
}
-static int cgroup_write_notify_on_release(struct cgroup *cgrp,
- struct cftype *cft,
- u64 val)
+static int cgroup_write_notify_on_release(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
{
- clear_bit(CGRP_RELEASABLE, &cgrp->flags);
+ clear_bit(CGRP_RELEASABLE, &css->cgroup->flags);
if (val)
- set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
+ set_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
else
- clear_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
+ clear_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
return 0;
}
@@ -3895,18 +3959,18 @@ static void cgroup_event_remove(struct work_struct *work)
{
struct cgroup_event *event = container_of(work, struct cgroup_event,
remove);
- struct cgroup *cgrp = event->cgrp;
+ struct cgroup_subsys_state *css = event->css;
remove_wait_queue(event->wqh, &event->wait);
- event->cft->unregister_event(cgrp, event->cft, event->eventfd);
+ event->cft->unregister_event(css, event->cft, event->eventfd);
/* Notify userspace the event is going away. */
eventfd_signal(event->eventfd, 1);
eventfd_ctx_put(event->eventfd);
kfree(event);
- cgroup_dput(cgrp);
+ css_put(css);
}
/*
@@ -3919,7 +3983,7 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
{
struct cgroup_event *event = container_of(wait,
struct cgroup_event, wait);
- struct cgroup *cgrp = event->cgrp;
+ struct cgroup *cgrp = event->css->cgroup;
unsigned long flags = (unsigned long)key;
if (flags & POLLHUP) {
@@ -3963,14 +4027,15 @@ static void cgroup_event_ptable_queue_proc(struct file *file,
* Input must be in format '<event_fd> <control_fd> <args>'.
* Interpretation of args is defined by control file implementation.
*/
-static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
- const char *buffer)
+static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css,
+ struct cftype *cft, const char *buffer)
{
- struct cgroup_event *event = NULL;
- struct cgroup *cgrp_cfile;
+ struct cgroup *cgrp = dummy_css->cgroup;
+ struct cgroup_event *event;
+ struct cgroup_subsys_state *cfile_css;
unsigned int efd, cfd;
- struct file *efile = NULL;
- struct file *cfile = NULL;
+ struct file *efile;
+ struct file *cfile;
char *endp;
int ret;
@@ -3987,7 +4052,7 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event)
return -ENOMEM;
- event->cgrp = cgrp;
+
INIT_LIST_HEAD(&event->list);
init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc);
init_waitqueue_func_entry(&event->wait, cgroup_event_wake);
@@ -3996,62 +4061,68 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
efile = eventfd_fget(efd);
if (IS_ERR(efile)) {
ret = PTR_ERR(efile);
- goto fail;
+ goto out_kfree;
}
event->eventfd = eventfd_ctx_fileget(efile);
if (IS_ERR(event->eventfd)) {
ret = PTR_ERR(event->eventfd);
- goto fail;
+ goto out_put_efile;
}
cfile = fget(cfd);
if (!cfile) {
ret = -EBADF;
- goto fail;
+ goto out_put_eventfd;
}
/* the process need read permission on control file */
/* AV: shouldn't we check that it's been opened for read instead? */
ret = inode_permission(file_inode(cfile), MAY_READ);
if (ret < 0)
- goto fail;
+ goto out_put_cfile;
event->cft = __file_cft(cfile);
if (IS_ERR(event->cft)) {
ret = PTR_ERR(event->cft);
- goto fail;
+ goto out_put_cfile;
+ }
+
+ if (!event->cft->ss) {
+ ret = -EBADF;
+ goto out_put_cfile;
}
/*
- * The file to be monitored must be in the same cgroup as
- * cgroup.event_control is.
+ * Determine the css of @cfile, verify it belongs to the same
+ * cgroup as cgroup.event_control, and associate @event with it.
+ * Remaining events are automatically removed on cgroup destruction
+ * but the removal is asynchronous, so take an extra ref.
*/
- cgrp_cfile = __d_cgrp(cfile->f_dentry->d_parent);
- if (cgrp_cfile != cgrp) {
- ret = -EINVAL;
- goto fail;
- }
+ rcu_read_lock();
+
+ ret = -EINVAL;
+ event->css = cgroup_css(cgrp, event->cft->ss);
+ cfile_css = css_from_dir(cfile->f_dentry->d_parent, event->cft->ss);
+ if (event->css && event->css == cfile_css && css_tryget(event->css))
+ ret = 0;
+
+ rcu_read_unlock();
+ if (ret)
+ goto out_put_cfile;
if (!event->cft->register_event || !event->cft->unregister_event) {
ret = -EINVAL;
- goto fail;
+ goto out_put_css;
}
- ret = event->cft->register_event(cgrp, event->cft,
+ ret = event->cft->register_event(event->css, event->cft,
event->eventfd, buffer);
if (ret)
- goto fail;
+ goto out_put_css;
efile->f_op->poll(efile, &event->pt);
- /*
- * Events should be removed after rmdir of cgroup directory, but before
- * destroying subsystem state objects. Let's take reference to cgroup
- * directory dentry to do that.
- */
- dget(cgrp->dentry);
-
spin_lock(&cgrp->event_list_lock);
list_add(&event->list, &cgrp->event_list);
spin_unlock(&cgrp->event_list_lock);
@@ -4061,35 +4132,33 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
return 0;
-fail:
- if (cfile)
- fput(cfile);
-
- if (event && event->eventfd && !IS_ERR(event->eventfd))
- eventfd_ctx_put(event->eventfd);
-
- if (!IS_ERR_OR_NULL(efile))
- fput(efile);
-
+out_put_css:
+ css_put(event->css);
+out_put_cfile:
+ fput(cfile);
+out_put_eventfd:
+ eventfd_ctx_put(event->eventfd);
+out_put_efile:
+ fput(efile);
+out_kfree:
kfree(event);
return ret;
}
-static u64 cgroup_clone_children_read(struct cgroup *cgrp,
- struct cftype *cft)
+static u64 cgroup_clone_children_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
+ return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
}
-static int cgroup_clone_children_write(struct cgroup *cgrp,
- struct cftype *cft,
- u64 val)
+static int cgroup_clone_children_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
{
if (val)
- set_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
+ set_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
else
- clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
+ clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
return 0;
}
@@ -4148,36 +4217,34 @@ static struct cftype cgroup_base_files[] = {
};
/**
- * cgroup_populate_dir - selectively creation of files in a directory
+ * cgroup_populate_dir - create subsys files in a cgroup directory
* @cgrp: target cgroup
- * @base_files: true if the base files should be added
* @subsys_mask: mask of the subsystem ids whose files should be added
+ *
+ * On failure, no file is added.
*/
-static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files,
- unsigned long subsys_mask)
+static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask)
{
- int err;
struct cgroup_subsys *ss;
-
- if (base_files) {
- err = cgroup_addrm_files(cgrp, NULL, cgroup_base_files, true);
- if (err < 0)
- return err;
- }
+ int i, ret = 0;
/* process cftsets of each subsystem */
- for_each_root_subsys(cgrp->root, ss) {
+ for_each_subsys(ss, i) {
struct cftype_set *set;
- if (!test_bit(ss->subsys_id, &subsys_mask))
+
+ if (!test_bit(i, &subsys_mask))
continue;
- list_for_each_entry(set, &ss->cftsets, node)
- cgroup_addrm_files(cgrp, ss, set->cfts, true);
+ list_for_each_entry(set, &ss->cftsets, node) {
+ ret = cgroup_addrm_files(cgrp, set->cfts, true);
+ if (ret < 0)
+ goto err;
+ }
}
/* This cgroup is ready now */
for_each_root_subsys(cgrp->root, ss) {
- struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+ struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
struct css_id *id = rcu_dereference_protected(css->id, true);
/*
@@ -4190,14 +4257,57 @@ static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files,
}
return 0;
+err:
+ cgroup_clear_dir(cgrp, subsys_mask);
+ return ret;
+}
+
+/*
+ * css destruction is four-stage process.
+ *
+ * 1. Destruction starts. Killing of the percpu_ref is initiated.
+ * Implemented in kill_css().
+ *
+ * 2. When the percpu_ref is confirmed to be visible as killed on all CPUs
+ * and thus css_tryget() is guaranteed to fail, the css can be offlined
+ * by invoking offline_css(). After offlining, the base ref is put.
+ * Implemented in css_killed_work_fn().
+ *
+ * 3. When the percpu_ref reaches zero, the only possible remaining
+ * accessors are inside RCU read sections. css_release() schedules the
+ * RCU callback.
+ *
+ * 4. After the grace period, the css can be freed. Implemented in
+ * css_free_work_fn().
+ *
+ * It is actually hairier because both step 2 and 4 require process context
+ * and thus involve punting to css->destroy_work adding two additional
+ * steps to the already complex sequence.
+ */
+static void css_free_work_fn(struct work_struct *work)
+{
+ struct cgroup_subsys_state *css =
+ container_of(work, struct cgroup_subsys_state, destroy_work);
+ struct cgroup *cgrp = css->cgroup;
+
+ if (css->parent)
+ css_put(css->parent);
+
+ css->ss->css_free(css);
+ cgroup_dput(cgrp);
}
-static void css_dput_fn(struct work_struct *work)
+static void css_free_rcu_fn(struct rcu_head *rcu_head)
{
struct cgroup_subsys_state *css =
- container_of(work, struct cgroup_subsys_state, dput_work);
+ container_of(rcu_head, struct cgroup_subsys_state, rcu_head);
- cgroup_dput(css->cgroup);
+ /*
+ * css holds an extra ref to @cgrp->dentry which is put on the last
+ * css_put(). dput() requires process context which we don't have.
+ */
+ INIT_WORK(&css->destroy_work, css_free_work_fn);
+ schedule_work(&css->destroy_work);
}
static void css_release(struct percpu_ref *ref)
@@ -4205,49 +4315,47 @@ static void css_release(struct percpu_ref *ref)
struct cgroup_subsys_state *css =
container_of(ref, struct cgroup_subsys_state, refcnt);
- schedule_work(&css->dput_work);
+ call_rcu(&css->rcu_head, css_free_rcu_fn);
}
-static void init_cgroup_css(struct cgroup_subsys_state *css,
- struct cgroup_subsys *ss,
- struct cgroup *cgrp)
+static void init_css(struct cgroup_subsys_state *css, struct cgroup_subsys *ss,
+ struct cgroup *cgrp)
{
css->cgroup = cgrp;
+ css->ss = ss;
css->flags = 0;
css->id = NULL;
- if (cgrp == cgroup_dummy_top)
+
+ if (cgrp->parent)
+ css->parent = cgroup_css(cgrp->parent, ss);
+ else
css->flags |= CSS_ROOT;
- BUG_ON(cgrp->subsys[ss->subsys_id]);
- cgrp->subsys[ss->subsys_id] = css;
- /*
- * css holds an extra ref to @cgrp->dentry which is put on the last
- * css_put(). dput() requires process context, which css_put() may
- * be called without. @css->dput_work will be used to invoke
- * dput() asynchronously from css_put().
- */
- INIT_WORK(&css->dput_work, css_dput_fn);
+ BUG_ON(cgroup_css(cgrp, ss));
}
-/* invoke ->post_create() on a new CSS and mark it online if successful */
-static int online_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
+/* invoke ->css_online() on a new CSS and mark it online if successful */
+static int online_css(struct cgroup_subsys_state *css)
{
+ struct cgroup_subsys *ss = css->ss;
int ret = 0;
lockdep_assert_held(&cgroup_mutex);
if (ss->css_online)
- ret = ss->css_online(cgrp);
- if (!ret)
- cgrp->subsys[ss->subsys_id]->flags |= CSS_ONLINE;
+ ret = ss->css_online(css);
+ if (!ret) {
+ css->flags |= CSS_ONLINE;
+ css->cgroup->nr_css++;
+ rcu_assign_pointer(css->cgroup->subsys[ss->subsys_id], css);
+ }
return ret;
}
-/* if the CSS is online, invoke ->pre_destory() on it and mark it offline */
-static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
- __releases(&cgroup_mutex) __acquires(&cgroup_mutex)
+/* if the CSS is online, invoke ->css_offline() on it and mark it offline */
+static void offline_css(struct cgroup_subsys_state *css)
{
- struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+ struct cgroup_subsys *ss = css->ss;
lockdep_assert_held(&cgroup_mutex);
@@ -4255,9 +4363,11 @@ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
return;
if (ss->css_offline)
- ss->css_offline(cgrp);
+ ss->css_offline(css);
- cgrp->subsys[ss->subsys_id]->flags &= ~CSS_ONLINE;
+ css->flags &= ~CSS_ONLINE;
+ css->cgroup->nr_css--;
+ RCU_INIT_POINTER(css->cgroup->subsys[ss->subsys_id], css);
}
/*
@@ -4271,6 +4381,7 @@ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
umode_t mode)
{
+ struct cgroup_subsys_state *css_ar[CGROUP_SUBSYS_COUNT] = { };
struct cgroup *cgrp;
struct cgroup_name *name;
struct cgroupfs_root *root = parent->root;
@@ -4288,7 +4399,11 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
goto err_free_cgrp;
rcu_assign_pointer(cgrp->name, name);
- cgrp->id = ida_simple_get(&root->cgroup_ida, 1, 0, GFP_KERNEL);
+ /*
+ * Temporarily set the pointer to NULL, so idr_find() won't return
+ * a half-baked cgroup.
+ */
+ cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL);
if (cgrp->id < 0)
goto err_free_name;
@@ -4317,6 +4432,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
cgrp->dentry = dentry;
cgrp->parent = parent;
+ cgrp->dummy_css.parent = &parent->dummy_css;
cgrp->root = parent->root;
if (notify_on_release(parent))
@@ -4328,22 +4444,21 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
for_each_root_subsys(root, ss) {
struct cgroup_subsys_state *css;
- css = ss->css_alloc(cgrp);
+ css = ss->css_alloc(cgroup_css(parent, ss));
if (IS_ERR(css)) {
err = PTR_ERR(css);
goto err_free_all;
}
+ css_ar[ss->subsys_id] = css;
err = percpu_ref_init(&css->refcnt, css_release);
- if (err) {
- ss->css_free(cgrp);
+ if (err)
goto err_free_all;
- }
- init_cgroup_css(css, ss, cgrp);
+ init_css(css, ss, cgrp);
if (ss->use_id) {
- err = alloc_css_id(ss, parent, cgrp);
+ err = alloc_css_id(css);
if (err)
goto err_free_all;
}
@@ -4365,16 +4480,22 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children);
root->number_of_cgroups++;
- /* each css holds a ref to the cgroup's dentry */
- for_each_root_subsys(root, ss)
+ /* each css holds a ref to the cgroup's dentry and the parent css */
+ for_each_root_subsys(root, ss) {
+ struct cgroup_subsys_state *css = css_ar[ss->subsys_id];
+
dget(dentry);
+ css_get(css->parent);
+ }
/* hold a ref to the parent's dentry */
dget(parent->dentry);
/* creation succeeded, notify subsystems */
for_each_root_subsys(root, ss) {
- err = online_css(ss, cgrp);
+ struct cgroup_subsys_state *css = css_ar[ss->subsys_id];
+
+ err = online_css(css);
if (err)
goto err_destroy;
@@ -4388,7 +4509,13 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
}
}
- err = cgroup_populate_dir(cgrp, true, root->subsys_mask);
+ idr_replace(&root->cgroup_idr, cgrp, cgrp->id);
+
+ err = cgroup_addrm_files(cgrp, cgroup_base_files, true);
+ if (err)
+ goto err_destroy;
+
+ err = cgroup_populate_dir(cgrp, root->subsys_mask);
if (err)
goto err_destroy;
@@ -4399,18 +4526,18 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
err_free_all:
for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+ struct cgroup_subsys_state *css = css_ar[ss->subsys_id];
if (css) {
percpu_ref_cancel_init(&css->refcnt);
- ss->css_free(cgrp);
+ ss->css_free(css);
}
}
mutex_unlock(&cgroup_mutex);
/* Release the reference count that we took on the superblock */
deactivate_super(sb);
err_free_id:
- ida_simple_remove(&root->cgroup_ida, cgrp->id);
+ idr_remove(&root->cgroup_idr, cgrp->id);
err_free_name:
kfree(rcu_dereference_raw(cgrp->name));
err_free_cgrp:
@@ -4432,22 +4559,84 @@ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
return cgroup_create(c_parent, dentry, mode | S_IFDIR);
}
-static void cgroup_css_killed(struct cgroup *cgrp)
+/*
+ * This is called when the refcnt of a css is confirmed to be killed.
+ * css_tryget() is now guaranteed to fail.
+ */
+static void css_killed_work_fn(struct work_struct *work)
{
- if (!atomic_dec_and_test(&cgrp->css_kill_cnt))
- return;
+ struct cgroup_subsys_state *css =
+ container_of(work, struct cgroup_subsys_state, destroy_work);
+ struct cgroup *cgrp = css->cgroup;
- /* percpu ref's of all css's are killed, kick off the next step */
- INIT_WORK(&cgrp->destroy_work, cgroup_offline_fn);
- schedule_work(&cgrp->destroy_work);
+ mutex_lock(&cgroup_mutex);
+
+ /*
+ * css_tryget() is guaranteed to fail now. Tell subsystems to
+ * initate destruction.
+ */
+ offline_css(css);
+
+ /*
+ * If @cgrp is marked dead, it's waiting for refs of all css's to
+ * be disabled before proceeding to the second phase of cgroup
+ * destruction. If we are the last one, kick it off.
+ */
+ if (!cgrp->nr_css && cgroup_is_dead(cgrp))
+ cgroup_destroy_css_killed(cgrp);
+
+ mutex_unlock(&cgroup_mutex);
+
+ /*
+ * Put the css refs from kill_css(). Each css holds an extra
+ * reference to the cgroup's dentry and cgroup removal proceeds
+ * regardless of css refs. On the last put of each css, whenever
+ * that may be, the extra dentry ref is put so that dentry
+ * destruction happens only after all css's are released.
+ */
+ css_put(css);
}
-static void css_ref_killed_fn(struct percpu_ref *ref)
+/* css kill confirmation processing requires process context, bounce */
+static void css_killed_ref_fn(struct percpu_ref *ref)
{
struct cgroup_subsys_state *css =
container_of(ref, struct cgroup_subsys_state, refcnt);
- cgroup_css_killed(css->cgroup);
+ INIT_WORK(&css->destroy_work, css_killed_work_fn);
+ schedule_work(&css->destroy_work);
+}
+
+/**
+ * kill_css - destroy a css
+ * @css: css to destroy
+ *
+ * This function initiates destruction of @css by removing cgroup interface
+ * files and putting its base reference. ->css_offline() will be invoked
+ * asynchronously once css_tryget() is guaranteed to fail and when the
+ * reference count reaches zero, @css will be released.
+ */
+static void kill_css(struct cgroup_subsys_state *css)
+{
+ cgroup_clear_dir(css->cgroup, 1 << css->ss->subsys_id);
+
+ /*
+ * Killing would put the base ref, but we need to keep it alive
+ * until after ->css_offline().
+ */
+ css_get(css);
+
+ /*
+ * cgroup core guarantees that, by the time ->css_offline() is
+ * invoked, no new css reference will be given out via
+ * css_tryget(). We can't simply call percpu_ref_kill() and
+ * proceed to offlining css's because percpu_ref_kill() doesn't
+ * guarantee that the ref is seen as killed on all CPUs on return.
+ *
+ * Use percpu_ref_kill_and_confirm() to get notifications as each
+ * css is confirmed to be seen as killed on all CPUs.
+ */
+ percpu_ref_kill_and_confirm(&css->refcnt, css_killed_ref_fn);
}
/**
@@ -4480,6 +4669,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
struct dentry *d = cgrp->dentry;
struct cgroup_event *event, *tmp;
struct cgroup_subsys *ss;
+ struct cgroup *child;
bool empty;
lockdep_assert_held(&d->d_inode->i_mutex);
@@ -4490,47 +4680,41 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
* @cgrp from being removed while __put_css_set() is in progress.
*/
read_lock(&css_set_lock);
- empty = list_empty(&cgrp->cset_links) && list_empty(&cgrp->children);
+ empty = list_empty(&cgrp->cset_links);
read_unlock(&css_set_lock);
if (!empty)
return -EBUSY;
/*
- * Block new css_tryget() by killing css refcnts. cgroup core
- * guarantees that, by the time ->css_offline() is invoked, no new
- * css reference will be given out via css_tryget(). We can't
- * simply call percpu_ref_kill() and proceed to offlining css's
- * because percpu_ref_kill() doesn't guarantee that the ref is seen
- * as killed on all CPUs on return.
- *
- * Use percpu_ref_kill_and_confirm() to get notifications as each
- * css is confirmed to be seen as killed on all CPUs. The
- * notification callback keeps track of the number of css's to be
- * killed and schedules cgroup_offline_fn() to perform the rest of
- * destruction once the percpu refs of all css's are confirmed to
- * be killed.
+ * Make sure there's no live children. We can't test ->children
+ * emptiness as dead children linger on it while being destroyed;
+ * otherwise, "rmdir parent/child parent" may fail with -EBUSY.
*/
- atomic_set(&cgrp->css_kill_cnt, 1);
- for_each_root_subsys(cgrp->root, ss) {
- struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
-
- /*
- * Killing would put the base ref, but we need to keep it
- * alive until after ->css_offline.
- */
- percpu_ref_get(&css->refcnt);
-
- atomic_inc(&cgrp->css_kill_cnt);
- percpu_ref_kill_and_confirm(&css->refcnt, css_ref_killed_fn);
+ empty = true;
+ rcu_read_lock();
+ list_for_each_entry_rcu(child, &cgrp->children, sibling) {
+ empty = cgroup_is_dead(child);
+ if (!empty)
+ break;
}
- cgroup_css_killed(cgrp);
+ rcu_read_unlock();
+ if (!empty)
+ return -EBUSY;
+
+ /*
+ * Initiate massacre of all css's. cgroup_destroy_css_killed()
+ * will be invoked to perform the rest of destruction once the
+ * percpu refs of all css's are confirmed to be killed.
+ */
+ for_each_root_subsys(cgrp->root, ss)
+ kill_css(cgroup_css(cgrp, ss));
/*
* Mark @cgrp dead. This prevents further task migration and child
* creation by disabling cgroup_lock_live_group(). Note that
- * CGRP_DEAD assertion is depended upon by cgroup_next_sibling() to
+ * CGRP_DEAD assertion is depended upon by css_next_child() to
* resume iteration after dropping RCU read lock. See
- * cgroup_next_sibling() for details.
+ * css_next_child() for details.
*/
set_bit(CGRP_DEAD, &cgrp->flags);
@@ -4541,9 +4725,20 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
raw_spin_unlock(&release_list_lock);
/*
- * Remove @cgrp directory. The removal puts the base ref but we
- * aren't quite done with @cgrp yet, so hold onto it.
+ * If @cgrp has css's attached, the second stage of cgroup
+ * destruction is kicked off from css_killed_work_fn() after the
+ * refs of all attached css's are killed. If @cgrp doesn't have
+ * any css, we kick it off here.
*/
+ if (!cgrp->nr_css)
+ cgroup_destroy_css_killed(cgrp);
+
+ /*
+ * Clear the base files and remove @cgrp directory. The removal
+ * puts the base ref but we aren't quite done with @cgrp yet, so
+ * hold onto it.
+ */
+ cgroup_addrm_files(cgrp, cgroup_base_files, false);
dget(d);
cgroup_d_remove_dir(d);
@@ -4563,50 +4758,36 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
};
/**
- * cgroup_offline_fn - the second step of cgroup destruction
+ * cgroup_destroy_css_killed - the second step of cgroup destruction
* @work: cgroup->destroy_free_work
*
* This function is invoked from a work item for a cgroup which is being
- * destroyed after the percpu refcnts of all css's are guaranteed to be
- * seen as killed on all CPUs, and performs the rest of destruction. This
- * is the second step of destruction described in the comment above
- * cgroup_destroy_locked().
+ * destroyed after all css's are offlined and performs the rest of
+ * destruction. This is the second step of destruction described in the
+ * comment above cgroup_destroy_locked().
*/
-static void cgroup_offline_fn(struct work_struct *work)
+static void cgroup_destroy_css_killed(struct cgroup *cgrp)
{
- struct cgroup *cgrp = container_of(work, struct cgroup, destroy_work);
struct cgroup *parent = cgrp->parent;
struct dentry *d = cgrp->dentry;
- struct cgroup_subsys *ss;
- mutex_lock(&cgroup_mutex);
+ lockdep_assert_held(&cgroup_mutex);
- /*
- * css_tryget() is guaranteed to fail now. Tell subsystems to
- * initate destruction.
- */
- for_each_root_subsys(cgrp->root, ss)
- offline_css(ss, cgrp);
+ /* delete this cgroup from parent->children */
+ list_del_rcu(&cgrp->sibling);
/*
- * Put the css refs from cgroup_destroy_locked(). Each css holds
- * an extra reference to the cgroup's dentry and cgroup removal
- * proceeds regardless of css refs. On the last put of each css,
- * whenever that may be, the extra dentry ref is put so that dentry
- * destruction happens only after all css's are released.
+ * We should remove the cgroup object from idr before its grace
+ * period starts, so we won't be looking up a cgroup while the
+ * cgroup is being freed.
*/
- for_each_root_subsys(cgrp->root, ss)
- css_put(cgrp->subsys[ss->subsys_id]);
-
- /* delete this cgroup from parent->children */
- list_del_rcu(&cgrp->sibling);
+ idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
+ cgrp->id = -1;
dput(d);
set_bit(CGRP_RELEASABLE, &parent->flags);
check_for_release(parent);
-
- mutex_unlock(&cgroup_mutex);
}
static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
@@ -4629,6 +4810,11 @@ static void __init_or_module cgroup_init_cftsets(struct cgroup_subsys *ss)
* deregistration.
*/
if (ss->base_cftypes) {
+ struct cftype *cft;
+
+ for (cft = ss->base_cftypes; cft->name[0] != '\0'; cft++)
+ cft->ss = ss;
+
ss->base_cftset.cfts = ss->base_cftypes;
list_add_tail(&ss->base_cftset.node, &ss->cftsets);
}
@@ -4648,10 +4834,10 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
/* Create the top cgroup state for this subsystem */
list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
ss->root = &cgroup_dummy_root;
- css = ss->css_alloc(cgroup_dummy_top);
+ css = ss->css_alloc(cgroup_css(cgroup_dummy_top, ss));
/* We don't handle early failures gracefully */
BUG_ON(IS_ERR(css));
- init_cgroup_css(css, ss, cgroup_dummy_top);
+ init_css(css, ss, cgroup_dummy_top);
/* Update the init_css_set to contain a subsys
* pointer to this state - since the subsystem is
@@ -4666,7 +4852,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
* need to invoke fork callbacks here. */
BUG_ON(!list_empty(&init_task.tasks));
- BUG_ON(online_css(ss, cgroup_dummy_top));
+ BUG_ON(online_css(css));
mutex_unlock(&cgroup_mutex);
@@ -4727,7 +4913,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
* struct, so this can happen first (i.e. before the dummy root
* attachment).
*/
- css = ss->css_alloc(cgroup_dummy_top);
+ css = ss->css_alloc(cgroup_css(cgroup_dummy_top, ss));
if (IS_ERR(css)) {
/* failure case - need to deassign the cgroup_subsys[] slot. */
cgroup_subsys[ss->subsys_id] = NULL;
@@ -4739,8 +4925,8 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
ss->root = &cgroup_dummy_root;
/* our new subsystem will be attached to the dummy hierarchy. */
- init_cgroup_css(css, ss, cgroup_dummy_top);
- /* init_idr must be after init_cgroup_css because it sets css->id. */
+ init_css(css, ss, cgroup_dummy_top);
+ /* init_idr must be after init_css() because it sets css->id. */
if (ss->use_id) {
ret = cgroup_init_idr(ss, css);
if (ret)
@@ -4770,7 +4956,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
}
write_unlock(&css_set_lock);
- ret = online_css(ss, cgroup_dummy_top);
+ ret = online_css(css);
if (ret)
goto err_unload;
@@ -4802,14 +4988,14 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
/*
* we shouldn't be called if the subsystem is in use, and the use of
- * try_module_get in parse_cgroupfs_options should ensure that it
+ * try_module_get() in rebind_subsystems() should ensure that it
* doesn't start being used while we're killing it off.
*/
BUG_ON(ss->root != &cgroup_dummy_root);
mutex_lock(&cgroup_mutex);
- offline_css(ss, cgroup_dummy_top);
+ offline_css(cgroup_css(cgroup_dummy_top, ss));
if (ss->use_id)
idr_destroy(&ss->idr);
@@ -4843,8 +5029,8 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
* the cgrp->subsys pointer to find their state. note that this
* also takes care of freeing the css_id.
*/
- ss->css_free(cgroup_dummy_top);
- cgroup_dummy_top->subsys[ss->subsys_id] = NULL;
+ ss->css_free(cgroup_css(cgroup_dummy_top, ss));
+ RCU_INIT_POINTER(cgroup_dummy_top->subsys[ss->subsys_id], NULL);
mutex_unlock(&cgroup_mutex);
}
@@ -4926,6 +5112,10 @@ int __init cgroup_init(void)
BUG_ON(cgroup_init_root_id(&cgroup_dummy_root, 0, 1));
+ err = idr_alloc(&cgroup_dummy_root.cgroup_idr, cgroup_dummy_top,
+ 0, 1, GFP_KERNEL);
+ BUG_ON(err < 0);
+
mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
@@ -5082,7 +5272,7 @@ void cgroup_fork(struct task_struct *child)
* Adds the task to the list running through its css_set if necessary and
* call the subsystem fork() callbacks. Has to be after the task is
* visible on the task list in case we race with the first call to
- * cgroup_iter_start() - to guarantee that the new task ends up on its
+ * cgroup_task_iter_start() - to guarantee that the new task ends up on its
* list.
*/
void cgroup_post_fork(struct task_struct *child)
@@ -5195,10 +5385,10 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
*/
for_each_builtin_subsys(ss, i) {
if (ss->exit) {
- struct cgroup *old_cgrp = cset->subsys[i]->cgroup;
- struct cgroup *cgrp = task_cgroup(tsk, i);
+ struct cgroup_subsys_state *old_css = cset->subsys[i];
+ struct cgroup_subsys_state *css = task_css(tsk, i);
- ss->exit(cgrp, old_cgrp, tsk);
+ ss->exit(css, old_css, tsk);
}
}
}
@@ -5457,20 +5647,16 @@ static int __init_or_module cgroup_init_idr(struct cgroup_subsys *ss,
return 0;
}
-static int alloc_css_id(struct cgroup_subsys *ss, struct cgroup *parent,
- struct cgroup *child)
+static int alloc_css_id(struct cgroup_subsys_state *child_css)
{
- int subsys_id, i, depth = 0;
- struct cgroup_subsys_state *parent_css, *child_css;
+ struct cgroup_subsys_state *parent_css = css_parent(child_css);
struct css_id *child_id, *parent_id;
+ int i, depth;
- subsys_id = ss->subsys_id;
- parent_css = parent->subsys[subsys_id];
- child_css = child->subsys[subsys_id];
parent_id = rcu_dereference_protected(parent_css->id, true);
depth = parent_id->depth + 1;
- child_id = get_new_cssid(ss, depth);
+ child_id = get_new_cssid(child_css->ss, depth);
if (IS_ERR(child_id))
return PTR_ERR(child_id);
@@ -5508,31 +5694,56 @@ struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id)
}
EXPORT_SYMBOL_GPL(css_lookup);
-/*
- * get corresponding css from file open on cgroupfs directory
+/**
+ * css_from_dir - get corresponding css from the dentry of a cgroup dir
+ * @dentry: directory dentry of interest
+ * @ss: subsystem of interest
+ *
+ * Must be called under RCU read lock. The caller is responsible for
+ * pinning the returned css if it needs to be accessed outside the RCU
+ * critical section.
*/
-struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id)
+struct cgroup_subsys_state *css_from_dir(struct dentry *dentry,
+ struct cgroup_subsys *ss)
{
struct cgroup *cgrp;
- struct inode *inode;
- struct cgroup_subsys_state *css;
- inode = file_inode(f);
- /* check in cgroup filesystem dir */
- if (inode->i_op != &cgroup_dir_inode_operations)
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ /* is @dentry a cgroup dir? */
+ if (!dentry->d_inode ||
+ dentry->d_inode->i_op != &cgroup_dir_inode_operations)
return ERR_PTR(-EBADF);
- if (id < 0 || id >= CGROUP_SUBSYS_COUNT)
- return ERR_PTR(-EINVAL);
+ cgrp = __d_cgrp(dentry);
+ return cgroup_css(cgrp, ss) ?: ERR_PTR(-ENOENT);
+}
- /* get cgroup */
- cgrp = __d_cgrp(f->f_dentry);
- css = cgrp->subsys[id];
- return css ? css : ERR_PTR(-ENOENT);
+/**
+ * css_from_id - lookup css by id
+ * @id: the cgroup id
+ * @ss: cgroup subsys to be looked into
+ *
+ * Returns the css if there's valid one with @id, otherwise returns NULL.
+ * Should be called under rcu_read_lock().
+ */
+struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss)
+{
+ struct cgroup *cgrp;
+
+ rcu_lockdep_assert(rcu_read_lock_held() ||
+ lockdep_is_held(&cgroup_mutex),
+ "css_from_id() needs proper protection");
+
+ cgrp = idr_find(&ss->root->cgroup_idr, id);
+ if (cgrp)
+ return cgroup_css(cgrp, ss);
+ return NULL;
}
#ifdef CONFIG_CGROUP_DEBUG
-static struct cgroup_subsys_state *debug_css_alloc(struct cgroup *cgrp)
+static struct cgroup_subsys_state *
+debug_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
@@ -5542,22 +5753,24 @@ static struct cgroup_subsys_state *debug_css_alloc(struct cgroup *cgrp)
return css;
}
-static void debug_css_free(struct cgroup *cgrp)
+static void debug_css_free(struct cgroup_subsys_state *css)
{
- kfree(cgrp->subsys[debug_subsys_id]);
+ kfree(css);
}
-static u64 debug_taskcount_read(struct cgroup *cgrp, struct cftype *cft)
+static u64 debug_taskcount_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return cgroup_task_count(cgrp);
+ return cgroup_task_count(css->cgroup);
}
-static u64 current_css_set_read(struct cgroup *cgrp, struct cftype *cft)
+static u64 current_css_set_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
return (u64)(unsigned long)current->cgroups;
}
-static u64 current_css_set_refcount_read(struct cgroup *cgrp,
+static u64 current_css_set_refcount_read(struct cgroup_subsys_state *css,
struct cftype *cft)
{
u64 count;
@@ -5568,7 +5781,7 @@ static u64 current_css_set_refcount_read(struct cgroup *cgrp,
return count;
}
-static int current_css_set_cg_links_read(struct cgroup *cgrp,
+static int current_css_set_cg_links_read(struct cgroup_subsys_state *css,
struct cftype *cft,
struct seq_file *seq)
{
@@ -5595,14 +5808,13 @@ static int current_css_set_cg_links_read(struct cgroup *cgrp,
}
#define MAX_TASKS_SHOWN_PER_CSS 25
-static int cgroup_css_links_read(struct cgroup *cgrp,
- struct cftype *cft,
- struct seq_file *seq)
+static int cgroup_css_links_read(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *seq)
{
struct cgrp_cset_link *link;
read_lock(&css_set_lock);
- list_for_each_entry(link, &cgrp->cset_links, cset_link) {
+ list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {
struct css_set *cset = link->cset;
struct task_struct *task;
int count = 0;
@@ -5621,9 +5833,9 @@ static int cgroup_css_links_read(struct cgroup *cgrp,
return 0;
}
-static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft)
+static u64 releasable_read(struct cgroup_subsys_state *css, struct cftype *cft)
{
- return test_bit(CGRP_RELEASABLE, &cgrp->flags);
+ return test_bit(CGRP_RELEASABLE, &css->cgroup->flags);
}
static struct cftype debug_files[] = {
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 75dda1ea5026..f0ff64d0ebaa 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -45,25 +45,19 @@ struct freezer {
spinlock_t lock;
};
-static inline struct freezer *cgroup_freezer(struct cgroup *cgroup)
+static inline struct freezer *css_freezer(struct cgroup_subsys_state *css)
{
- return container_of(cgroup_subsys_state(cgroup, freezer_subsys_id),
- struct freezer, css);
+ return css ? container_of(css, struct freezer, css) : NULL;
}
static inline struct freezer *task_freezer(struct task_struct *task)
{
- return container_of(task_subsys_state(task, freezer_subsys_id),
- struct freezer, css);
+ return css_freezer(task_css(task, freezer_subsys_id));
}
static struct freezer *parent_freezer(struct freezer *freezer)
{
- struct cgroup *pcg = freezer->css.cgroup->parent;
-
- if (pcg)
- return cgroup_freezer(pcg);
- return NULL;
+ return css_freezer(css_parent(&freezer->css));
}
bool cgroup_freezing(struct task_struct *task)
@@ -92,7 +86,8 @@ static const char *freezer_state_strs(unsigned int state)
struct cgroup_subsys freezer_subsys;
-static struct cgroup_subsys_state *freezer_css_alloc(struct cgroup *cgroup)
+static struct cgroup_subsys_state *
+freezer_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct freezer *freezer;
@@ -105,22 +100,22 @@ static struct cgroup_subsys_state *freezer_css_alloc(struct cgroup *cgroup)
}
/**
- * freezer_css_online - commit creation of a freezer cgroup
- * @cgroup: cgroup being created
+ * freezer_css_online - commit creation of a freezer css
+ * @css: css being created
*
- * We're committing to creation of @cgroup. Mark it online and inherit
+ * We're committing to creation of @css. Mark it online and inherit
* parent's freezing state while holding both parent's and our
* freezer->lock.
*/
-static int freezer_css_online(struct cgroup *cgroup)
+static int freezer_css_online(struct cgroup_subsys_state *css)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
struct freezer *parent = parent_freezer(freezer);
/*
* The following double locking and freezing state inheritance
* guarantee that @cgroup can never escape ancestors' freezing
- * states. See cgroup_for_each_descendant_pre() for details.
+ * states. See css_for_each_descendant_pre() for details.
*/
if (parent)
spin_lock_irq(&parent->lock);
@@ -141,15 +136,15 @@ static int freezer_css_online(struct cgroup *cgroup)
}
/**
- * freezer_css_offline - initiate destruction of @cgroup
- * @cgroup: cgroup being destroyed
+ * freezer_css_offline - initiate destruction of a freezer css
+ * @css: css being destroyed
*
- * @cgroup is going away. Mark it dead and decrement system_freezing_count
- * if it was holding one.
+ * @css is going away. Mark it dead and decrement system_freezing_count if
+ * it was holding one.
*/
-static void freezer_css_offline(struct cgroup *cgroup)
+static void freezer_css_offline(struct cgroup_subsys_state *css)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
spin_lock_irq(&freezer->lock);
@@ -161,9 +156,9 @@ static void freezer_css_offline(struct cgroup *cgroup)
spin_unlock_irq(&freezer->lock);
}
-static void freezer_css_free(struct cgroup *cgroup)
+static void freezer_css_free(struct cgroup_subsys_state *css)
{
- kfree(cgroup_freezer(cgroup));
+ kfree(css_freezer(css));
}
/*
@@ -175,25 +170,26 @@ static void freezer_css_free(struct cgroup *cgroup)
* @freezer->lock. freezer_attach() makes the new tasks conform to the
* current state and all following state changes can see the new tasks.
*/
-static void freezer_attach(struct cgroup *new_cgrp, struct cgroup_taskset *tset)
+static void freezer_attach(struct cgroup_subsys_state *new_css,
+ struct cgroup_taskset *tset)
{
- struct freezer *freezer = cgroup_freezer(new_cgrp);
+ struct freezer *freezer = css_freezer(new_css);
struct task_struct *task;
bool clear_frozen = false;
spin_lock_irq(&freezer->lock);
/*
- * Make the new tasks conform to the current state of @new_cgrp.
+ * Make the new tasks conform to the current state of @new_css.
* For simplicity, when migrating any task to a FROZEN cgroup, we
* revert it to FREEZING and let update_if_frozen() determine the
* correct state later.
*
- * Tasks in @tset are on @new_cgrp but may not conform to its
+ * Tasks in @tset are on @new_css but may not conform to its
* current state before executing the following - !frozen tasks may
* be visible in a FROZEN cgroup and frozen tasks in a THAWED one.
*/
- cgroup_taskset_for_each(task, new_cgrp, tset) {
+ cgroup_taskset_for_each(task, new_css, tset) {
if (!(freezer->state & CGROUP_FREEZING)) {
__thaw_task(task);
} else {
@@ -231,7 +227,7 @@ static void freezer_fork(struct task_struct *task)
* The root cgroup is non-freezable, so we can skip the
* following check.
*/
- if (!freezer->css.cgroup->parent)
+ if (!parent_freezer(freezer))
goto out;
spin_lock_irq(&freezer->lock);
@@ -244,7 +240,7 @@ out:
/**
* update_if_frozen - update whether a cgroup finished freezing
- * @cgroup: cgroup of interest
+ * @css: css of interest
*
* Once FREEZING is initiated, transition to FROZEN is lazily updated by
* calling this function. If the current state is FREEZING but not FROZEN,
@@ -255,14 +251,14 @@ out:
* update_if_frozen() on all descendants prior to invoking this function.
*
* Task states and freezer state might disagree while tasks are being
- * migrated into or out of @cgroup, so we can't verify task states against
+ * migrated into or out of @css, so we can't verify task states against
* @freezer state here. See freezer_attach() for details.
*/
-static void update_if_frozen(struct cgroup *cgroup)
+static void update_if_frozen(struct cgroup_subsys_state *css)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
- struct cgroup *pos;
- struct cgroup_iter it;
+ struct freezer *freezer = css_freezer(css);
+ struct cgroup_subsys_state *pos;
+ struct css_task_iter it;
struct task_struct *task;
WARN_ON_ONCE(!rcu_read_lock_held());
@@ -274,8 +270,8 @@ static void update_if_frozen(struct cgroup *cgroup)
goto out_unlock;
/* are all (live) children frozen? */
- cgroup_for_each_child(pos, cgroup) {
- struct freezer *child = cgroup_freezer(pos);
+ css_for_each_child(pos, css) {
+ struct freezer *child = css_freezer(pos);
if ((child->state & CGROUP_FREEZER_ONLINE) &&
!(child->state & CGROUP_FROZEN))
@@ -283,9 +279,9 @@ static void update_if_frozen(struct cgroup *cgroup)
}
/* are all tasks frozen? */
- cgroup_iter_start(cgroup, &it);
+ css_task_iter_start(css, &it);
- while ((task = cgroup_iter_next(cgroup, &it))) {
+ while ((task = css_task_iter_next(&it))) {
if (freezing(task)) {
/*
* freezer_should_skip() indicates that the task
@@ -300,52 +296,49 @@ static void update_if_frozen(struct cgroup *cgroup)
freezer->state |= CGROUP_FROZEN;
out_iter_end:
- cgroup_iter_end(cgroup, &it);
+ css_task_iter_end(&it);
out_unlock:
spin_unlock_irq(&freezer->lock);
}
-static int freezer_read(struct cgroup *cgroup, struct cftype *cft,
+static int freezer_read(struct cgroup_subsys_state *css, struct cftype *cft,
struct seq_file *m)
{
- struct cgroup *pos;
+ struct cgroup_subsys_state *pos;
rcu_read_lock();
/* update states bottom-up */
- cgroup_for_each_descendant_post(pos, cgroup)
+ css_for_each_descendant_post(pos, css)
update_if_frozen(pos);
- update_if_frozen(cgroup);
rcu_read_unlock();
- seq_puts(m, freezer_state_strs(cgroup_freezer(cgroup)->state));
+ seq_puts(m, freezer_state_strs(css_freezer(css)->state));
seq_putc(m, '\n');
return 0;
}
static void freeze_cgroup(struct freezer *freezer)
{
- struct cgroup *cgroup = freezer->css.cgroup;
- struct cgroup_iter it;
+ struct css_task_iter it;
struct task_struct *task;
- cgroup_iter_start(cgroup, &it);
- while ((task = cgroup_iter_next(cgroup, &it)))
+ css_task_iter_start(&freezer->css, &it);
+ while ((task = css_task_iter_next(&it)))
freeze_task(task);
- cgroup_iter_end(cgroup, &it);
+ css_task_iter_end(&it);
}
static void unfreeze_cgroup(struct freezer *freezer)
{
- struct cgroup *cgroup = freezer->css.cgroup;
- struct cgroup_iter it;
+ struct css_task_iter it;
struct task_struct *task;
- cgroup_iter_start(cgroup, &it);
- while ((task = cgroup_iter_next(cgroup, &it)))
+ css_task_iter_start(&freezer->css, &it);
+ while ((task = css_task_iter_next(&it)))
__thaw_task(task);
- cgroup_iter_end(cgroup, &it);
+ css_task_iter_end(&it);
}
/**
@@ -395,12 +388,7 @@ static void freezer_apply_state(struct freezer *freezer, bool freeze,
*/
static void freezer_change_state(struct freezer *freezer, bool freeze)
{
- struct cgroup *pos;
-
- /* update @freezer */
- spin_lock_irq(&freezer->lock);
- freezer_apply_state(freezer, freeze, CGROUP_FREEZING_SELF);
- spin_unlock_irq(&freezer->lock);
+ struct cgroup_subsys_state *pos;
/*
* Update all its descendants in pre-order traversal. Each
@@ -408,24 +396,33 @@ static void freezer_change_state(struct freezer *freezer, bool freeze)
* CGROUP_FREEZING_PARENT.
*/
rcu_read_lock();
- cgroup_for_each_descendant_pre(pos, freezer->css.cgroup) {
- struct freezer *pos_f = cgroup_freezer(pos);
+ css_for_each_descendant_pre(pos, &freezer->css) {
+ struct freezer *pos_f = css_freezer(pos);
struct freezer *parent = parent_freezer(pos_f);
- /*
- * Our update to @parent->state is already visible which is
- * all we need. No need to lock @parent. For more info on
- * synchronization, see freezer_post_create().
- */
spin_lock_irq(&pos_f->lock);
- freezer_apply_state(pos_f, parent->state & CGROUP_FREEZING,
- CGROUP_FREEZING_PARENT);
+
+ if (pos_f == freezer) {
+ freezer_apply_state(pos_f, freeze,
+ CGROUP_FREEZING_SELF);
+ } else {
+ /*
+ * Our update to @parent->state is already visible
+ * which is all we need. No need to lock @parent.
+ * For more info on synchronization, see
+ * freezer_post_create().
+ */
+ freezer_apply_state(pos_f,
+ parent->state & CGROUP_FREEZING,
+ CGROUP_FREEZING_PARENT);
+ }
+
spin_unlock_irq(&pos_f->lock);
}
rcu_read_unlock();
}
-static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
+static int freezer_write(struct cgroup_subsys_state *css, struct cftype *cft,
const char *buffer)
{
bool freeze;
@@ -437,20 +434,22 @@ static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
else
return -EINVAL;
- freezer_change_state(cgroup_freezer(cgroup), freeze);
+ freezer_change_state(css_freezer(css), freeze);
return 0;
}
-static u64 freezer_self_freezing_read(struct cgroup *cgroup, struct cftype *cft)
+static u64 freezer_self_freezing_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
return (bool)(freezer->state & CGROUP_FREEZING_SELF);
}
-static u64 freezer_parent_freezing_read(struct cgroup *cgroup, struct cftype *cft)
+static u64 freezer_parent_freezing_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
return (bool)(freezer->state & CGROUP_FREEZING_PARENT);
}
diff --git a/kernel/cpu.c b/kernel/cpu.c
index b2b227b82123..d7f07a2da5a6 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -113,7 +113,7 @@ EXPORT_SYMBOL_GPL(put_online_cpus);
* get_online_cpus() not an api which is called all that often.
*
*/
-static void cpu_hotplug_begin(void)
+void cpu_hotplug_begin(void)
{
cpu_hotplug.active_writer = current;
@@ -127,7 +127,7 @@ static void cpu_hotplug_begin(void)
}
}
-static void cpu_hotplug_done(void)
+void cpu_hotplug_done(void)
{
cpu_hotplug.active_writer = NULL;
mutex_unlock(&cpu_hotplug.lock);
@@ -154,10 +154,7 @@ void cpu_hotplug_enable(void)
cpu_maps_update_done();
}
-#else /* #if CONFIG_HOTPLUG_CPU */
-static void cpu_hotplug_begin(void) {}
-static void cpu_hotplug_done(void) {}
-#endif /* #else #if CONFIG_HOTPLUG_CPU */
+#endif /* CONFIG_HOTPLUG_CPU */
/* Need to know about CPUs going up/down? */
int __ref register_cpu_notifier(struct notifier_block *nb)
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index ea1966db34f2..6bf981e13c43 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -68,10 +68,6 @@
*/
int number_of_cpusets __read_mostly;
-/* Forward declare cgroup structures */
-struct cgroup_subsys cpuset_subsys;
-struct cpuset;
-
/* See "Frequency meter" comments, below. */
struct fmeter {
@@ -115,27 +111,20 @@ struct cpuset {
int relax_domain_level;
};
-/* Retrieve the cpuset for a cgroup */
-static inline struct cpuset *cgroup_cs(struct cgroup *cgrp)
+static inline struct cpuset *css_cs(struct cgroup_subsys_state *css)
{
- return container_of(cgroup_subsys_state(cgrp, cpuset_subsys_id),
- struct cpuset, css);
+ return css ? container_of(css, struct cpuset, css) : NULL;
}
/* Retrieve the cpuset for a task */
static inline struct cpuset *task_cs(struct task_struct *task)
{
- return container_of(task_subsys_state(task, cpuset_subsys_id),
- struct cpuset, css);
+ return css_cs(task_css(task, cpuset_subsys_id));
}
-static inline struct cpuset *parent_cs(const struct cpuset *cs)
+static inline struct cpuset *parent_cs(struct cpuset *cs)
{
- struct cgroup *pcgrp = cs->css.cgroup->parent;
-
- if (pcgrp)
- return cgroup_cs(pcgrp);
- return NULL;
+ return css_cs(css_parent(&cs->css));
}
#ifdef CONFIG_NUMA
@@ -212,29 +201,30 @@ static struct cpuset top_cpuset = {
/**
* cpuset_for_each_child - traverse online children of a cpuset
* @child_cs: loop cursor pointing to the current child
- * @pos_cgrp: used for iteration
+ * @pos_css: used for iteration
* @parent_cs: target cpuset to walk children of
*
* Walk @child_cs through the online children of @parent_cs. Must be used
* with RCU read locked.
*/
-#define cpuset_for_each_child(child_cs, pos_cgrp, parent_cs) \
- cgroup_for_each_child((pos_cgrp), (parent_cs)->css.cgroup) \
- if (is_cpuset_online(((child_cs) = cgroup_cs((pos_cgrp)))))
+#define cpuset_for_each_child(child_cs, pos_css, parent_cs) \
+ css_for_each_child((pos_css), &(parent_cs)->css) \
+ if (is_cpuset_online(((child_cs) = css_cs((pos_css)))))
/**
* cpuset_for_each_descendant_pre - pre-order walk of a cpuset's descendants
* @des_cs: loop cursor pointing to the current descendant
- * @pos_cgrp: used for iteration
+ * @pos_css: used for iteration
* @root_cs: target cpuset to walk ancestor of
*
* Walk @des_cs through the online descendants of @root_cs. Must be used
- * with RCU read locked. The caller may modify @pos_cgrp by calling
- * cgroup_rightmost_descendant() to skip subtree.
+ * with RCU read locked. The caller may modify @pos_css by calling
+ * css_rightmost_descendant() to skip subtree. @root_cs is included in the
+ * iteration and the first node to be visited.
*/
-#define cpuset_for_each_descendant_pre(des_cs, pos_cgrp, root_cs) \
- cgroup_for_each_descendant_pre((pos_cgrp), (root_cs)->css.cgroup) \
- if (is_cpuset_online(((des_cs) = cgroup_cs((pos_cgrp)))))
+#define cpuset_for_each_descendant_pre(des_cs, pos_css, root_cs) \
+ css_for_each_descendant_pre((pos_css), &(root_cs)->css) \
+ if (is_cpuset_online(((des_cs) = css_cs((pos_css)))))
/*
* There are two global mutexes guarding cpuset structures - cpuset_mutex
@@ -320,8 +310,7 @@ static struct file_system_type cpuset_fs_type = {
*
* Call with callback_mutex held.
*/
-static void guarantee_online_cpus(const struct cpuset *cs,
- struct cpumask *pmask)
+static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
{
while (!cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
cs = parent_cs(cs);
@@ -339,7 +328,7 @@ static void guarantee_online_cpus(const struct cpuset *cs,
*
* Call with callback_mutex held.
*/
-static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
+static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask)
{
while (!nodes_intersects(cs->mems_allowed, node_states[N_MEMORY]))
cs = parent_cs(cs);
@@ -384,7 +373,7 @@ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
* alloc_trial_cpuset - allocate a trial cpuset
* @cs: the cpuset that the trial cpuset duplicates
*/
-static struct cpuset *alloc_trial_cpuset(const struct cpuset *cs)
+static struct cpuset *alloc_trial_cpuset(struct cpuset *cs)
{
struct cpuset *trial;
@@ -431,9 +420,9 @@ static void free_trial_cpuset(struct cpuset *trial)
* Return 0 if valid, -errno if not.
*/
-static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
+static int validate_change(struct cpuset *cur, struct cpuset *trial)
{
- struct cgroup *cgrp;
+ struct cgroup_subsys_state *css;
struct cpuset *c, *par;
int ret;
@@ -441,7 +430,7 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
/* Each of our child cpusets must be a subset of us */
ret = -EBUSY;
- cpuset_for_each_child(c, cgrp, cur)
+ cpuset_for_each_child(c, css, cur)
if (!is_cpuset_subset(c, trial))
goto out;
@@ -462,7 +451,7 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
* overlap
*/
ret = -EINVAL;
- cpuset_for_each_child(c, cgrp, par) {
+ cpuset_for_each_child(c, css, par) {
if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
c != cur &&
cpumask_intersects(trial->cpus_allowed, c->cpus_allowed))
@@ -515,13 +504,16 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr,
struct cpuset *root_cs)
{
struct cpuset *cp;
- struct cgroup *pos_cgrp;
+ struct cgroup_subsys_state *pos_css;
rcu_read_lock();
- cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) {
+ cpuset_for_each_descendant_pre(cp, pos_css, root_cs) {
+ if (cp == root_cs)
+ continue;
+
/* skip the whole subtree if @cp doesn't have any CPU */
if (cpumask_empty(cp->cpus_allowed)) {
- pos_cgrp = cgroup_rightmost_descendant(pos_cgrp);
+ pos_css = css_rightmost_descendant(pos_css);
continue;
}
@@ -596,7 +588,7 @@ static int generate_sched_domains(cpumask_var_t **domains,
struct sched_domain_attr *dattr; /* attributes for custom domains */
int ndoms = 0; /* number of sched domains in result */
int nslot; /* next empty doms[] struct cpumask slot */
- struct cgroup *pos_cgrp;
+ struct cgroup_subsys_state *pos_css;
doms = NULL;
dattr = NULL;
@@ -625,7 +617,9 @@ static int generate_sched_domains(cpumask_var_t **domains,
csn = 0;
rcu_read_lock();
- cpuset_for_each_descendant_pre(cp, pos_cgrp, &top_cpuset) {
+ cpuset_for_each_descendant_pre(cp, pos_css, &top_cpuset) {
+ if (cp == &top_cpuset)
+ continue;
/*
* Continue traversing beyond @cp iff @cp has some CPUs and
* isn't load balancing. The former is obvious. The
@@ -642,7 +636,7 @@ static int generate_sched_domains(cpumask_var_t **domains,
csa[csn++] = cp;
/* skip @cp's subtree */
- pos_cgrp = cgroup_rightmost_descendant(pos_cgrp);
+ pos_css = css_rightmost_descendant(pos_css);
}
rcu_read_unlock();
@@ -837,52 +831,45 @@ static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs)
/**
* cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's
* @tsk: task to test
- * @scan: struct cgroup_scanner containing the cgroup of the task
+ * @data: cpuset to @tsk belongs to
*
- * Called by cgroup_scan_tasks() for each task in a cgroup whose
- * cpus_allowed mask needs to be changed.
+ * Called by css_scan_tasks() for each task in a cgroup whose cpus_allowed
+ * mask needs to be changed.
*
* We don't need to re-check for the cgroup/cpuset membership, since we're
* holding cpuset_mutex at this point.
*/
-static void cpuset_change_cpumask(struct task_struct *tsk,
- struct cgroup_scanner *scan)
+static void cpuset_change_cpumask(struct task_struct *tsk, void *data)
{
- struct cpuset *cpus_cs;
+ struct cpuset *cs = data;
+ struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
- cpus_cs = effective_cpumask_cpuset(cgroup_cs(scan->cg));
set_cpus_allowed_ptr(tsk, cpus_cs->cpus_allowed);
}
/**
* update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
* @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
- * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
+ * @heap: if NULL, defer allocating heap memory to css_scan_tasks()
*
* Called with cpuset_mutex held
*
- * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
+ * The css_scan_tasks() function will scan all the tasks in a cgroup,
* calling callback functions for each.
*
- * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
+ * No return value. It's guaranteed that css_scan_tasks() always returns 0
* if @heap != NULL.
*/
static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap)
{
- struct cgroup_scanner scan;
-
- scan.cg = cs->css.cgroup;
- scan.test_task = NULL;
- scan.process_task = cpuset_change_cpumask;
- scan.heap = heap;
- cgroup_scan_tasks(&scan);
+ css_scan_tasks(&cs->css, NULL, cpuset_change_cpumask, cs, heap);
}
/*
* update_tasks_cpumask_hier - Update the cpumasks of tasks in the hierarchy.
* @root_cs: the root cpuset of the hierarchy
* @update_root: update root cpuset or not?
- * @heap: the heap used by cgroup_scan_tasks()
+ * @heap: the heap used by css_scan_tasks()
*
* This will update cpumasks of tasks in @root_cs and all other empty cpusets
* which take on cpumask of @root_cs.
@@ -893,17 +880,19 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs,
bool update_root, struct ptr_heap *heap)
{
struct cpuset *cp;
- struct cgroup *pos_cgrp;
-
- if (update_root)
- update_tasks_cpumask(root_cs, heap);
+ struct cgroup_subsys_state *pos_css;
rcu_read_lock();
- cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) {
- /* skip the whole subtree if @cp have some CPU */
- if (!cpumask_empty(cp->cpus_allowed)) {
- pos_cgrp = cgroup_rightmost_descendant(pos_cgrp);
- continue;
+ cpuset_for_each_descendant_pre(cp, pos_css, root_cs) {
+ if (cp == root_cs) {
+ if (!update_root)
+ continue;
+ } else {
+ /* skip the whole subtree if @cp have some CPU */
+ if (!cpumask_empty(cp->cpus_allowed)) {
+ pos_css = css_rightmost_descendant(pos_css);
+ continue;
+ }
}
if (!css_tryget(&cp->css))
continue;
@@ -1059,20 +1048,24 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
task_unlock(tsk);
}
+struct cpuset_change_nodemask_arg {
+ struct cpuset *cs;
+ nodemask_t *newmems;
+};
+
/*
* Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy
* of it to cpuset's new mems_allowed, and migrate pages to new nodes if
* memory_migrate flag is set. Called with cpuset_mutex held.
*/
-static void cpuset_change_nodemask(struct task_struct *p,
- struct cgroup_scanner *scan)
+static void cpuset_change_nodemask(struct task_struct *p, void *data)
{
- struct cpuset *cs = cgroup_cs(scan->cg);
+ struct cpuset_change_nodemask_arg *arg = data;
+ struct cpuset *cs = arg->cs;
struct mm_struct *mm;
int migrate;
- nodemask_t *newmems = scan->data;
- cpuset_change_task_nodemask(p, newmems);
+ cpuset_change_task_nodemask(p, arg->newmems);
mm = get_task_mm(p);
if (!mm)
@@ -1082,7 +1075,7 @@ static void cpuset_change_nodemask(struct task_struct *p,
mpol_rebind_mm(mm, &cs->mems_allowed);
if (migrate)
- cpuset_migrate_mm(mm, &cs->old_mems_allowed, newmems);
+ cpuset_migrate_mm(mm, &cs->old_mems_allowed, arg->newmems);
mmput(mm);
}
@@ -1091,28 +1084,22 @@ static void *cpuset_being_rebound;
/**
* update_tasks_nodemask - Update the nodemasks of tasks in the cpuset.
* @cs: the cpuset in which each task's mems_allowed mask needs to be changed
- * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
+ * @heap: if NULL, defer allocating heap memory to css_scan_tasks()
*
- * Called with cpuset_mutex held
- * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
- * if @heap != NULL.
+ * Called with cpuset_mutex held. No return value. It's guaranteed that
+ * css_scan_tasks() always returns 0 if @heap != NULL.
*/
static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
{
static nodemask_t newmems; /* protected by cpuset_mutex */
- struct cgroup_scanner scan;
struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
+ struct cpuset_change_nodemask_arg arg = { .cs = cs,
+ .newmems = &newmems };
cpuset_being_rebound = cs; /* causes mpol_dup() rebind */
guarantee_online_mems(mems_cs, &newmems);
- scan.cg = cs->css.cgroup;
- scan.test_task = NULL;
- scan.process_task = cpuset_change_nodemask;
- scan.heap = heap;
- scan.data = &newmems;
-
/*
* The mpol_rebind_mm() call takes mmap_sem, which we couldn't
* take while holding tasklist_lock. Forks can happen - the
@@ -1123,7 +1110,7 @@ static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
* It's ok if we rebind the same mm twice; mpol_rebind_mm()
* is idempotent. Also migrate pages in each mm to new nodes.
*/
- cgroup_scan_tasks(&scan);
+ css_scan_tasks(&cs->css, NULL, cpuset_change_nodemask, &arg, heap);
/*
* All the tasks' nodemasks have been updated, update
@@ -1139,7 +1126,7 @@ static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
* update_tasks_nodemask_hier - Update the nodemasks of tasks in the hierarchy.
* @cs: the root cpuset of the hierarchy
* @update_root: update the root cpuset or not?
- * @heap: the heap used by cgroup_scan_tasks()
+ * @heap: the heap used by css_scan_tasks()
*
* This will update nodemasks of tasks in @root_cs and all other empty cpusets
* which take on nodemask of @root_cs.
@@ -1150,17 +1137,19 @@ static void update_tasks_nodemask_hier(struct cpuset *root_cs,
bool update_root, struct ptr_heap *heap)
{
struct cpuset *cp;
- struct cgroup *pos_cgrp;
-
- if (update_root)
- update_tasks_nodemask(root_cs, heap);
+ struct cgroup_subsys_state *pos_css;
rcu_read_lock();
- cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) {
- /* skip the whole subtree if @cp have some CPU */
- if (!nodes_empty(cp->mems_allowed)) {
- pos_cgrp = cgroup_rightmost_descendant(pos_cgrp);
- continue;
+ cpuset_for_each_descendant_pre(cp, pos_css, root_cs) {
+ if (cp == root_cs) {
+ if (!update_root)
+ continue;
+ } else {
+ /* skip the whole subtree if @cp have some CPU */
+ if (!nodes_empty(cp->mems_allowed)) {
+ pos_css = css_rightmost_descendant(pos_css);
+ continue;
+ }
}
if (!css_tryget(&cp->css))
continue;
@@ -1267,44 +1256,39 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
return 0;
}
-/*
+/**
* cpuset_change_flag - make a task's spread flags the same as its cpuset's
* @tsk: task to be updated
- * @scan: struct cgroup_scanner containing the cgroup of the task
+ * @data: cpuset to @tsk belongs to
*
- * Called by cgroup_scan_tasks() for each task in a cgroup.
+ * Called by css_scan_tasks() for each task in a cgroup.
*
* We don't need to re-check for the cgroup/cpuset membership, since we're
* holding cpuset_mutex at this point.
*/
-static void cpuset_change_flag(struct task_struct *tsk,
- struct cgroup_scanner *scan)
+static void cpuset_change_flag(struct task_struct *tsk, void *data)
{
- cpuset_update_task_spread_flag(cgroup_cs(scan->cg), tsk);
+ struct cpuset *cs = data;
+
+ cpuset_update_task_spread_flag(cs, tsk);
}
-/*
+/**
* update_tasks_flags - update the spread flags of tasks in the cpuset.
* @cs: the cpuset in which each task's spread flags needs to be changed
- * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
+ * @heap: if NULL, defer allocating heap memory to css_scan_tasks()
*
* Called with cpuset_mutex held
*
- * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
+ * The css_scan_tasks() function will scan all the tasks in a cgroup,
* calling callback functions for each.
*
- * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
+ * No return value. It's guaranteed that css_scan_tasks() always returns 0
* if @heap != NULL.
*/
static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap)
{
- struct cgroup_scanner scan;
-
- scan.cg = cs->css.cgroup;
- scan.test_task = NULL;
- scan.process_task = cpuset_change_flag;
- scan.heap = heap;
- cgroup_scan_tasks(&scan);
+ css_scan_tasks(&cs->css, NULL, cpuset_change_flag, cs, heap);
}
/*
@@ -1462,9 +1446,10 @@ static int fmeter_getrate(struct fmeter *fmp)
}
/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
-static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
+static int cpuset_can_attach(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
struct task_struct *task;
int ret;
@@ -1475,11 +1460,11 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
* flag is set.
*/
ret = -ENOSPC;
- if (!cgroup_sane_behavior(cgrp) &&
+ if (!cgroup_sane_behavior(css->cgroup) &&
(cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
goto out_unlock;
- cgroup_taskset_for_each(task, cgrp, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
/*
* Kthreads which disallow setaffinity shouldn't be moved
* to a new cpuset; we don't want to change their cpu
@@ -1508,11 +1493,11 @@ out_unlock:
return ret;
}
-static void cpuset_cancel_attach(struct cgroup *cgrp,
+static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
struct cgroup_taskset *tset)
{
mutex_lock(&cpuset_mutex);
- cgroup_cs(cgrp)->attach_in_progress--;
+ css_cs(css)->attach_in_progress--;
mutex_unlock(&cpuset_mutex);
}
@@ -1523,16 +1508,18 @@ static void cpuset_cancel_attach(struct cgroup *cgrp,
*/
static cpumask_var_t cpus_attach;
-static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
+static void cpuset_attach(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
{
/* static buf protected by cpuset_mutex */
static nodemask_t cpuset_attach_nodemask_to;
struct mm_struct *mm;
struct task_struct *task;
struct task_struct *leader = cgroup_taskset_first(tset);
- struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset);
- struct cpuset *cs = cgroup_cs(cgrp);
- struct cpuset *oldcs = cgroup_cs(oldcgrp);
+ struct cgroup_subsys_state *oldcss = cgroup_taskset_cur_css(tset,
+ cpuset_subsys_id);
+ struct cpuset *cs = css_cs(css);
+ struct cpuset *oldcs = css_cs(oldcss);
struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
@@ -1546,7 +1533,7 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
guarantee_online_mems(mems_cs, &cpuset_attach_nodemask_to);
- cgroup_taskset_for_each(task, cgrp, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
/*
* can_attach beforehand should guarantee that this doesn't
* fail. TODO: have a better way to handle failure here
@@ -1608,9 +1595,10 @@ typedef enum {
FILE_SPREAD_SLAB,
} cpuset_filetype_t;
-static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
+static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
+ u64 val)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
cpuset_filetype_t type = cft->private;
int retval = 0;
@@ -1657,9 +1645,10 @@ out_unlock:
return retval;
}
-static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
+static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
+ s64 val)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
cpuset_filetype_t type = cft->private;
int retval = -ENODEV;
@@ -1683,10 +1672,10 @@ out_unlock:
/*
* Common handling for a write to a "cpus" or "mems" file.
*/
-static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
- const char *buf)
+static int cpuset_write_resmask(struct cgroup_subsys_state *css,
+ struct cftype *cft, const char *buf)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
struct cpuset *trialcs;
int retval = -ENODEV;
@@ -1765,13 +1754,12 @@ static size_t cpuset_sprintf_memlist(char *page, struct cpuset *cs)
return count;
}
-static ssize_t cpuset_common_file_read(struct cgroup *cgrp,
- struct cftype *cft,
- struct file *file,
- char __user *buf,
- size_t nbytes, loff_t *ppos)
+static ssize_t cpuset_common_file_read(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct file *file,
+ char __user *buf, size_t nbytes,
+ loff_t *ppos)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
cpuset_filetype_t type = cft->private;
char *page;
ssize_t retval = 0;
@@ -1801,9 +1789,9 @@ out:
return retval;
}
-static u64 cpuset_read_u64(struct cgroup *cgrp, struct cftype *cft)
+static u64 cpuset_read_u64(struct cgroup_subsys_state *css, struct cftype *cft)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
cpuset_filetype_t type = cft->private;
switch (type) {
case FILE_CPU_EXCLUSIVE:
@@ -1832,9 +1820,9 @@ static u64 cpuset_read_u64(struct cgroup *cgrp, struct cftype *cft)
return 0;
}
-static s64 cpuset_read_s64(struct cgroup *cgrp, struct cftype *cft)
+static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
cpuset_filetype_t type = cft->private;
switch (type) {
case FILE_SCHED_RELAX_DOMAIN_LEVEL:
@@ -1949,11 +1937,12 @@ static struct cftype files[] = {
* cgrp: control group that the new cpuset will be part of
*/
-static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cgrp)
+static struct cgroup_subsys_state *
+cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct cpuset *cs;
- if (!cgrp->parent)
+ if (!parent_css)
return &top_cpuset.css;
cs = kzalloc(sizeof(*cs), GFP_KERNEL);
@@ -1973,12 +1962,12 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cgrp)
return &cs->css;
}
-static int cpuset_css_online(struct cgroup *cgrp)
+static int cpuset_css_online(struct cgroup_subsys_state *css)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
struct cpuset *parent = parent_cs(cs);
struct cpuset *tmp_cs;
- struct cgroup *pos_cg;
+ struct cgroup_subsys_state *pos_css;
if (!parent)
return 0;
@@ -1993,7 +1982,7 @@ static int cpuset_css_online(struct cgroup *cgrp)
number_of_cpusets++;
- if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags))
+ if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))
goto out_unlock;
/*
@@ -2010,7 +1999,7 @@ static int cpuset_css_online(struct cgroup *cgrp)
* (and likewise for mems) to the new cgroup.
*/
rcu_read_lock();
- cpuset_for_each_child(tmp_cs, pos_cg, parent) {
+ cpuset_for_each_child(tmp_cs, pos_css, parent) {
if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) {
rcu_read_unlock();
goto out_unlock;
@@ -2027,9 +2016,15 @@ out_unlock:
return 0;
}
-static void cpuset_css_offline(struct cgroup *cgrp)
+/*
+ * If the cpuset being removed has its flag 'sched_load_balance'
+ * enabled, then simulate turning sched_load_balance off, which
+ * will call rebuild_sched_domains_locked().
+ */
+
+static void cpuset_css_offline(struct cgroup_subsys_state *css)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
mutex_lock(&cpuset_mutex);
@@ -2042,15 +2037,9 @@ static void cpuset_css_offline(struct cgroup *cgrp)
mutex_unlock(&cpuset_mutex);
}
-/*
- * If the cpuset being removed has its flag 'sched_load_balance'
- * enabled, then simulate turning sched_load_balance off, which
- * will call rebuild_sched_domains_locked().
- */
-
-static void cpuset_css_free(struct cgroup *cgrp)
+static void cpuset_css_free(struct cgroup_subsys_state *css)
{
- struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *cs = css_cs(css);
free_cpumask_var(cs->cpus_allowed);
kfree(cs);
@@ -2257,11 +2246,11 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
/* if cpus or mems changed, we need to propagate to descendants */
if (cpus_updated || mems_updated) {
struct cpuset *cs;
- struct cgroup *pos_cgrp;
+ struct cgroup_subsys_state *pos_css;
rcu_read_lock();
- cpuset_for_each_descendant_pre(cs, pos_cgrp, &top_cpuset) {
- if (!css_tryget(&cs->css))
+ cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) {
+ if (cs == &top_cpuset || !css_tryget(&cs->css))
continue;
rcu_read_unlock();
@@ -2350,7 +2339,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
{
- const struct cpuset *cpus_cs;
+ struct cpuset *cpus_cs;
rcu_read_lock();
cpus_cs = effective_cpumask_cpuset(task_cs(tsk));
@@ -2423,7 +2412,7 @@ int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
* callback_mutex. If no ancestor is mem_exclusive or mem_hardwall
* (an unusual configuration), then returns the root cpuset.
*/
-static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs)
+static struct cpuset *nearest_hardwall_ancestor(struct cpuset *cs)
{
while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && parent_cs(cs))
cs = parent_cs(cs);
@@ -2493,7 +2482,7 @@ static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs)
*/
int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
{
- const struct cpuset *cs; /* current cpuset ancestors */
+ struct cpuset *cs; /* current cpuset ancestors */
int allowed; /* is allocation in zone z allowed? */
if (in_interrupt() || (gfp_mask & __GFP_THISNODE))
@@ -2731,7 +2720,7 @@ int proc_cpuset_show(struct seq_file *m, void *unused_v)
goto out_free;
rcu_read_lock();
- css = task_subsys_state(tsk, cpuset_subsys_id);
+ css = task_css(tsk, cpuset_subsys_id);
retval = cgroup_path(css->cgroup, buf, PAGE_SIZE);
rcu_read_unlock();
if (retval < 0)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c7ee497c39a7..2207efc941d1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -341,8 +341,8 @@ struct perf_cgroup {
static inline struct perf_cgroup *
perf_cgroup_from_task(struct task_struct *task)
{
- return container_of(task_subsys_state(task, perf_subsys_id),
- struct perf_cgroup, css);
+ return container_of(task_css(task, perf_subsys_id),
+ struct perf_cgroup, css);
}
static inline bool
@@ -592,7 +592,9 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
if (!f.file)
return -EBADF;
- css = cgroup_css_from_dir(f.file, perf_subsys_id);
+ rcu_read_lock();
+
+ css = css_from_dir(f.file->f_dentry, &perf_subsys);
if (IS_ERR(css)) {
ret = PTR_ERR(css);
goto out;
@@ -618,6 +620,7 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
ret = -EINVAL;
}
out:
+ rcu_read_unlock();
fdput(f);
return ret;
}
@@ -2712,7 +2715,7 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
hwc = &event->hw;
- if (needs_unthr && hwc->interrupts == MAX_INTERRUPTS) {
+ if (hwc->interrupts == MAX_INTERRUPTS) {
hwc->interrupts = 0;
perf_log_throttle(event, 1);
event->pmu->start(event, 0);
@@ -7901,7 +7904,8 @@ unlock:
device_initcall(perf_event_sysfs_init);
#ifdef CONFIG_CGROUP_PERF
-static struct cgroup_subsys_state *perf_cgroup_css_alloc(struct cgroup *cont)
+static struct cgroup_subsys_state *
+perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct perf_cgroup *jc;
@@ -7918,11 +7922,10 @@ static struct cgroup_subsys_state *perf_cgroup_css_alloc(struct cgroup *cont)
return &jc->css;
}
-static void perf_cgroup_css_free(struct cgroup *cont)
+static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
{
- struct perf_cgroup *jc;
- jc = container_of(cgroup_subsys_state(cont, perf_subsys_id),
- struct perf_cgroup, css);
+ struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
+
free_percpu(jc->info);
kfree(jc);
}
@@ -7934,15 +7937,17 @@ static int __perf_cgroup_move(void *info)
return 0;
}
-static void perf_cgroup_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
+static void perf_cgroup_attach(struct cgroup_subsys_state *css,
+ struct cgroup_taskset *tset)
{
struct task_struct *task;
- cgroup_taskset_for_each(task, cgrp, tset)
+ cgroup_taskset_for_each(task, css, tset)
task_function_call(task, __perf_cgroup_move, task);
}
-static void perf_cgroup_exit(struct cgroup *cgrp, struct cgroup *old_cgrp,
+static void perf_cgroup_exit(struct cgroup_subsys_state *css,
+ struct cgroup_subsys_state *old_css,
struct task_struct *task)
{
/*
diff --git a/kernel/fork.c b/kernel/fork.c
index e23bb19e2a3e..bf46287c91a4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1177,7 +1177,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
* don't allow the creation of threads.
*/
if ((clone_flags & (CLONE_VM|CLONE_NEWPID)) &&
- (task_active_pid_ns(current) != current->nsproxy->pid_ns))
+ (task_active_pid_ns(current) !=
+ current->nsproxy->pid_ns_for_children))
return ERR_PTR(-EINVAL);
retval = security_task_create(clone_flags);
@@ -1351,7 +1352,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (pid != &init_struct_pid) {
retval = -ENOMEM;
- pid = alloc_pid(p->nsproxy->pid_ns);
+ pid = alloc_pid(p->nsproxy->pid_ns_for_children);
if (!pid)
goto bad_fork_cleanup_io;
}
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 6df614912b9d..3e97fb126e6b 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -15,6 +15,7 @@
#include <linux/lockdep.h>
#include <linux/export.h>
#include <linux/sysctl.h>
+#include <linux/utsname.h>
/*
* The number of tasks checked:
@@ -99,10 +100,14 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
* Ok, the task did not get scheduled for more than 2 minutes,
* complain:
*/
- printk(KERN_ERR "INFO: task %s:%d blocked for more than "
- "%ld seconds.\n", t->comm, t->pid, timeout);
- printk(KERN_ERR "\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
- " disables this message.\n");
+ pr_err("INFO: task %s:%d blocked for more than %ld seconds.\n",
+ t->comm, t->pid, timeout);
+ pr_err(" %s %s %.*s\n",
+ print_tainted(), init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+ pr_err("\"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\""
+ " disables this message.\n");
sched_show_task(t);
debug_show_held_locks(t);
diff --git a/kernel/lglock.c b/kernel/lglock.c
index 6535a667a5a7..86ae2aebf004 100644
--- a/kernel/lglock.c
+++ b/kernel/lglock.c
@@ -21,7 +21,7 @@ void lg_local_lock(struct lglock *lg)
arch_spinlock_t *lock;
preempt_disable();
- rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
+ lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
arch_spin_lock(lock);
}
@@ -31,7 +31,7 @@ void lg_local_unlock(struct lglock *lg)
{
arch_spinlock_t *lock;
- rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = this_cpu_ptr(lg->lock);
arch_spin_unlock(lock);
preempt_enable();
@@ -43,7 +43,7 @@ void lg_local_lock_cpu(struct lglock *lg, int cpu)
arch_spinlock_t *lock;
preempt_disable();
- rwlock_acquire_read(&lg->lock_dep_map, 0, 0, _RET_IP_);
+ lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
arch_spin_lock(lock);
}
@@ -53,7 +53,7 @@ void lg_local_unlock_cpu(struct lglock *lg, int cpu)
{
arch_spinlock_t *lock;
- rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ lock_release(&lg->lock_dep_map, 1, _RET_IP_);
lock = per_cpu_ptr(lg->lock, cpu);
arch_spin_unlock(lock);
preempt_enable();
@@ -65,7 +65,7 @@ void lg_global_lock(struct lglock *lg)
int i;
preempt_disable();
- rwlock_acquire(&lg->lock_dep_map, 0, 0, _RET_IP_);
+ lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
for_each_possible_cpu(i) {
arch_spinlock_t *lock;
lock = per_cpu_ptr(lg->lock, i);
@@ -78,7 +78,7 @@ void lg_global_unlock(struct lglock *lg)
{
int i;
- rwlock_release(&lg->lock_dep_map, 1, _RET_IP_);
+ lock_release(&lg->lock_dep_map, 1, _RET_IP_);
for_each_possible_cpu(i) {
arch_spinlock_t *lock;
lock = per_cpu_ptr(lg->lock, i);
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a52ee7bb830d..6d647aedffea 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -209,11 +209,13 @@ int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
*/
static inline int mutex_can_spin_on_owner(struct mutex *lock)
{
+ struct task_struct *owner;
int retval = 1;
rcu_read_lock();
- if (lock->owner)
- retval = lock->owner->on_cpu;
+ owner = ACCESS_ONCE(lock->owner);
+ if (owner)
+ retval = owner->on_cpu;
rcu_read_unlock();
/*
* if lock->owner is not set, the mutex owner may have just acquired
@@ -461,7 +463,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* performed the optimistic spinning cannot be done.
*/
if (ACCESS_ONCE(ww->ctx))
- break;
+ goto slowpath;
}
/*
@@ -472,7 +474,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
owner = ACCESS_ONCE(lock->owner);
if (owner && !mutex_spin_on_owner(lock, owner)) {
mspin_unlock(MLOCK(lock), &node);
- break;
+ goto slowpath;
}
if ((atomic_read(&lock->count) == 1) &&
@@ -499,7 +501,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* the owner complete.
*/
if (!owner && (need_resched() || rt_task(task)))
- break;
+ goto slowpath;
/*
* The cpu_relax() call is a compiler barrier which forces
@@ -513,6 +515,10 @@ slowpath:
#endif
spin_lock_mutex(&lock->wait_lock, flags);
+ /* once more, can we acquire the lock? */
+ if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, 0) == 1))
+ goto skip_wait;
+
debug_mutex_lock_common(lock, &waiter);
debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
@@ -520,9 +526,6 @@ slowpath:
list_add_tail(&waiter.list, &lock->wait_list);
waiter.task = task;
- if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, -1) == 1))
- goto done;
-
lock_contended(&lock->dep_map, ip);
for (;;) {
@@ -536,7 +539,7 @@ slowpath:
* other waiters:
*/
if (MUTEX_SHOW_NO_WAITER(lock) &&
- (atomic_xchg(&lock->count, -1) == 1))
+ (atomic_xchg(&lock->count, -1) == 1))
break;
/*
@@ -561,24 +564,25 @@ slowpath:
schedule_preempt_disabled();
spin_lock_mutex(&lock->wait_lock, flags);
}
+ mutex_remove_waiter(lock, &waiter, current_thread_info());
+ /* set it to 0 if there are no waiters left: */
+ if (likely(list_empty(&lock->wait_list)))
+ atomic_set(&lock->count, 0);
+ debug_mutex_free_waiter(&waiter);
-done:
+skip_wait:
+ /* got the lock - cleanup and rejoice! */
lock_acquired(&lock->dep_map, ip);
- /* got the lock - rejoice! */
- mutex_remove_waiter(lock, &waiter, current_thread_info());
mutex_set_owner(lock);
if (!__builtin_constant_p(ww_ctx == NULL)) {
- struct ww_mutex *ww = container_of(lock,
- struct ww_mutex,
- base);
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
struct mutex_waiter *cur;
/*
* This branch gets optimized out for the common case,
* and is only important for ww_mutex_lock.
*/
-
ww_mutex_lock_acquired(ww, ww_ctx);
ww->ctx = ww_ctx;
@@ -592,15 +596,8 @@ done:
}
}
- /* set it to 0 if there are no waiters left: */
- if (likely(list_empty(&lock->wait_list)))
- atomic_set(&lock->count, 0);
-
spin_unlock_mutex(&lock->wait_lock, flags);
-
- debug_mutex_free_waiter(&waiter);
preempt_enable();
-
return 0;
err:
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 364ceab15f0c..997cbb951a3b 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -29,15 +29,15 @@
static struct kmem_cache *nsproxy_cachep;
struct nsproxy init_nsproxy = {
- .count = ATOMIC_INIT(1),
- .uts_ns = &init_uts_ns,
+ .count = ATOMIC_INIT(1),
+ .uts_ns = &init_uts_ns,
#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
- .ipc_ns = &init_ipc_ns,
+ .ipc_ns = &init_ipc_ns,
#endif
- .mnt_ns = NULL,
- .pid_ns = &init_pid_ns,
+ .mnt_ns = NULL,
+ .pid_ns_for_children = &init_pid_ns,
#ifdef CONFIG_NET
- .net_ns = &init_net,
+ .net_ns = &init_net,
#endif
};
@@ -85,9 +85,10 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
goto out_ipc;
}
- new_nsp->pid_ns = copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns);
- if (IS_ERR(new_nsp->pid_ns)) {
- err = PTR_ERR(new_nsp->pid_ns);
+ new_nsp->pid_ns_for_children =
+ copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
+ if (IS_ERR(new_nsp->pid_ns_for_children)) {
+ err = PTR_ERR(new_nsp->pid_ns_for_children);
goto out_pid;
}
@@ -100,8 +101,8 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
return new_nsp;
out_net:
- if (new_nsp->pid_ns)
- put_pid_ns(new_nsp->pid_ns);
+ if (new_nsp->pid_ns_for_children)
+ put_pid_ns(new_nsp->pid_ns_for_children);
out_pid:
if (new_nsp->ipc_ns)
put_ipc_ns(new_nsp->ipc_ns);
@@ -174,8 +175,8 @@ void free_nsproxy(struct nsproxy *ns)
put_uts_ns(ns->uts_ns);
if (ns->ipc_ns)
put_ipc_ns(ns->ipc_ns);
- if (ns->pid_ns)
- put_pid_ns(ns->pid_ns);
+ if (ns->pid_ns_for_children)
+ put_pid_ns(ns->pid_ns_for_children);
put_net(ns->net_ns);
kmem_cache_free(nsproxy_cachep, ns);
}
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 6917e8edb48e..601bb361c235 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -349,8 +349,8 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns)
if (ancestor != active)
return -EINVAL;
- put_pid_ns(nsproxy->pid_ns);
- nsproxy->pid_ns = get_pid_ns(new);
+ put_pid_ns(nsproxy->pid_ns_for_children);
+ nsproxy->pid_ns_for_children = get_pid_ns(new);
return 0;
}
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index ece04223bb1e..62ee437b5c7e 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -210,6 +210,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
goto Platform_wake;
}
+ ftrace_stop();
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
goto Enable_cpus;
@@ -232,6 +233,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
Enable_cpus:
enable_nonboot_cpus();
+ ftrace_start();
Platform_wake:
if (need_suspend_ops(state) && suspend_ops->wake)
@@ -265,7 +267,6 @@ int suspend_devices_and_enter(suspend_state_t state)
goto Close;
}
suspend_console();
- ftrace_stop();
suspend_test_start();
error = dpm_suspend_start(PMSG_SUSPEND);
if (error) {
@@ -285,7 +286,6 @@ int suspend_devices_and_enter(suspend_state_t state)
suspend_test_start();
dpm_resume_end(PMSG_RESUME);
suspend_test_finish("resume devices");
- ftrace_start();
resume_console();
Close:
if (need_suspend_ops(state) && suspend_ops->end)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5b5a7080e2a5..b4e8500afdb3 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2226,6 +2226,13 @@ void register_console(struct console *newcon)
struct console *bcon = NULL;
struct console_cmdline *c;
+ if (console_drivers)
+ for_each_console(bcon)
+ if (WARN(bcon == newcon,
+ "console '%s%d' already registered\n",
+ bcon->name, bcon->index))
+ return;
+
/*
* before we register a new CON_BOOT console, make sure we don't
* already have a valid console
diff --git a/kernel/rcu.h b/kernel/rcu.h
index 7f8e7590e3e5..77131966c4ad 100644
--- a/kernel/rcu.h
+++ b/kernel/rcu.h
@@ -67,12 +67,15 @@
extern struct debug_obj_descr rcuhead_debug_descr;
-static inline void debug_rcu_head_queue(struct rcu_head *head)
+static inline int debug_rcu_head_queue(struct rcu_head *head)
{
- debug_object_activate(head, &rcuhead_debug_descr);
+ int r1;
+
+ r1 = debug_object_activate(head, &rcuhead_debug_descr);
debug_object_active_state(head, &rcuhead_debug_descr,
STATE_RCU_HEAD_READY,
STATE_RCU_HEAD_QUEUED);
+ return r1;
}
static inline void debug_rcu_head_unqueue(struct rcu_head *head)
@@ -83,8 +86,9 @@ static inline void debug_rcu_head_unqueue(struct rcu_head *head)
debug_object_deactivate(head, &rcuhead_debug_descr);
}
#else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
-static inline void debug_rcu_head_queue(struct rcu_head *head)
+static inline int debug_rcu_head_queue(struct rcu_head *head)
{
+ return 0;
}
static inline void debug_rcu_head_unqueue(struct rcu_head *head)
@@ -94,7 +98,7 @@ static inline void debug_rcu_head_unqueue(struct rcu_head *head)
extern void kfree(const void *);
-static inline bool __rcu_reclaim(char *rn, struct rcu_head *head)
+static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head)
{
unsigned long offset = (unsigned long)head->func;
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index cce6ba8bbace..33eb4620aa17 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -212,43 +212,6 @@ static inline void debug_rcu_head_free(struct rcu_head *head)
}
/*
- * fixup_init is called when:
- * - an active object is initialized
- */
-static int rcuhead_fixup_init(void *addr, enum debug_obj_state state)
-{
- struct rcu_head *head = addr;
-
- switch (state) {
- case ODEBUG_STATE_ACTIVE:
- /*
- * Ensure that queued callbacks are all executed.
- * If we detect that we are nested in a RCU read-side critical
- * section, we should simply fail, otherwise we would deadlock.
- * In !PREEMPT configurations, there is no way to tell if we are
- * in a RCU read-side critical section or not, so we never
- * attempt any fixup and just print a warning.
- */
-#ifndef CONFIG_PREEMPT
- WARN_ON_ONCE(1);
- return 0;
-#endif
- if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
- irqs_disabled()) {
- WARN_ON_ONCE(1);
- return 0;
- }
- rcu_barrier();
- rcu_barrier_sched();
- rcu_barrier_bh();
- debug_object_init(head, &rcuhead_debug_descr);
- return 1;
- default:
- return 0;
- }
-}
-
-/*
* fixup_activate is called when:
* - an active object is activated
* - an unknown object is activated (might be a statically initialized object)
@@ -268,69 +231,8 @@ static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state)
debug_object_init(head, &rcuhead_debug_descr);
debug_object_activate(head, &rcuhead_debug_descr);
return 0;
-
- case ODEBUG_STATE_ACTIVE:
- /*
- * Ensure that queued callbacks are all executed.
- * If we detect that we are nested in a RCU read-side critical
- * section, we should simply fail, otherwise we would deadlock.
- * In !PREEMPT configurations, there is no way to tell if we are
- * in a RCU read-side critical section or not, so we never
- * attempt any fixup and just print a warning.
- */
-#ifndef CONFIG_PREEMPT
- WARN_ON_ONCE(1);
- return 0;
-#endif
- if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
- irqs_disabled()) {
- WARN_ON_ONCE(1);
- return 0;
- }
- rcu_barrier();
- rcu_barrier_sched();
- rcu_barrier_bh();
- debug_object_activate(head, &rcuhead_debug_descr);
- return 1;
default:
- return 0;
- }
-}
-
-/*
- * fixup_free is called when:
- * - an active object is freed
- */
-static int rcuhead_fixup_free(void *addr, enum debug_obj_state state)
-{
- struct rcu_head *head = addr;
-
- switch (state) {
- case ODEBUG_STATE_ACTIVE:
- /*
- * Ensure that queued callbacks are all executed.
- * If we detect that we are nested in a RCU read-side critical
- * section, we should simply fail, otherwise we would deadlock.
- * In !PREEMPT configurations, there is no way to tell if we are
- * in a RCU read-side critical section or not, so we never
- * attempt any fixup and just print a warning.
- */
-#ifndef CONFIG_PREEMPT
- WARN_ON_ONCE(1);
- return 0;
-#endif
- if (rcu_preempt_depth() != 0 || preempt_count() != 0 ||
- irqs_disabled()) {
- WARN_ON_ONCE(1);
- return 0;
- }
- rcu_barrier();
- rcu_barrier_sched();
- rcu_barrier_bh();
- debug_object_free(head, &rcuhead_debug_descr);
return 1;
- default:
- return 0;
}
}
@@ -369,15 +271,13 @@ EXPORT_SYMBOL_GPL(destroy_rcu_head_on_stack);
struct debug_obj_descr rcuhead_debug_descr = {
.name = "rcu_head",
- .fixup_init = rcuhead_fixup_init,
.fixup_activate = rcuhead_fixup_activate,
- .fixup_free = rcuhead_fixup_free,
};
EXPORT_SYMBOL_GPL(rcuhead_debug_descr);
#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
#if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU) || defined(CONFIG_RCU_TRACE)
-void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp,
+void do_trace_rcu_torture_read(const char *rcutorturename, struct rcu_head *rhp,
unsigned long secs,
unsigned long c_old, unsigned long c)
{
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index aa344111de3e..9ed6075dc562 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -264,7 +264,7 @@ void rcu_check_callbacks(int cpu, int user)
*/
static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
{
- char *rn = NULL;
+ const char *rn = NULL;
struct rcu_head *next, *list;
unsigned long flags;
RCU_TRACE(int cb_count = 0);
diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h
index 0cd385acccfa..280d06cae352 100644
--- a/kernel/rcutiny_plugin.h
+++ b/kernel/rcutiny_plugin.h
@@ -36,7 +36,7 @@ struct rcu_ctrlblk {
RCU_TRACE(unsigned long gp_start); /* Start time for stalls. */
RCU_TRACE(unsigned long ticks_this_gp); /* Statistic for stalls. */
RCU_TRACE(unsigned long jiffies_stall); /* Jiffies at next stall. */
- RCU_TRACE(char *name); /* Name of RCU type. */
+ RCU_TRACE(const char *name); /* Name of RCU type. */
};
/* Definition for rcupdate control block. */
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index f4871e52c546..be63101c6175 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -52,72 +52,78 @@
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@freedesktop.org>");
-static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */
-static int nfakewriters = 4; /* # fake writer threads */
-static int stat_interval = 60; /* Interval between stats, in seconds. */
- /* Zero means "only at end of test". */
-static bool verbose; /* Print more debug info. */
-static bool test_no_idle_hz = true;
- /* Test RCU support for tickless idle CPUs. */
-static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
-static int stutter = 5; /* Start/stop testing interval (in sec) */
-static int irqreader = 1; /* RCU readers from irq (timers). */
-static int fqs_duration; /* Duration of bursts (us), 0 to disable. */
-static int fqs_holdoff; /* Hold time within burst (us). */
-static int fqs_stutter = 3; /* Wait time between bursts (s). */
-static int n_barrier_cbs; /* Number of callbacks to test RCU barriers. */
-static int onoff_interval; /* Wait time between CPU hotplugs, 0=disable. */
-static int onoff_holdoff; /* Seconds after boot before CPU hotplugs. */
-static int shutdown_secs; /* Shutdown time (s). <=0 for no shutdown. */
-static int stall_cpu; /* CPU-stall duration (s). 0 for no stall. */
-static int stall_cpu_holdoff = 10; /* Time to wait until stall (s). */
-static int test_boost = 1; /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */
-static int test_boost_interval = 7; /* Interval between boost tests, seconds. */
-static int test_boost_duration = 4; /* Duration of each boost test, seconds. */
-static char *torture_type = "rcu"; /* What RCU implementation to torture. */
-
-module_param(nreaders, int, 0444);
-MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
-module_param(nfakewriters, int, 0444);
-MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
-module_param(stat_interval, int, 0644);
-MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
-module_param(verbose, bool, 0444);
-MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
-module_param(test_no_idle_hz, bool, 0444);
-MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
-module_param(shuffle_interval, int, 0444);
-MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
-module_param(stutter, int, 0444);
-MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
-module_param(irqreader, int, 0444);
-MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
+static int fqs_duration;
module_param(fqs_duration, int, 0444);
-MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us)");
+MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us), 0 to disable");
+static int fqs_holdoff;
module_param(fqs_holdoff, int, 0444);
MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
+static int fqs_stutter = 3;
module_param(fqs_stutter, int, 0444);
MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
+static bool gp_exp;
+module_param(gp_exp, bool, 0444);
+MODULE_PARM_DESC(gp_exp, "Use expedited GP wait primitives");
+static bool gp_normal;
+module_param(gp_normal, bool, 0444);
+MODULE_PARM_DESC(gp_normal, "Use normal (non-expedited) GP wait primitives");
+static int irqreader = 1;
+module_param(irqreader, int, 0444);
+MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
+static int n_barrier_cbs;
module_param(n_barrier_cbs, int, 0444);
MODULE_PARM_DESC(n_barrier_cbs, "# of callbacks/kthreads for barrier testing");
-module_param(onoff_interval, int, 0444);
-MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
+static int nfakewriters = 4;
+module_param(nfakewriters, int, 0444);
+MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
+static int nreaders = -1;
+module_param(nreaders, int, 0444);
+MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
+static int object_debug;
+module_param(object_debug, int, 0444);
+MODULE_PARM_DESC(object_debug, "Enable debug-object double call_rcu() testing");
+static int onoff_holdoff;
module_param(onoff_holdoff, int, 0444);
MODULE_PARM_DESC(onoff_holdoff, "Time after boot before CPU hotplugs (s)");
+static int onoff_interval;
+module_param(onoff_interval, int, 0444);
+MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
+static int shuffle_interval = 3;
+module_param(shuffle_interval, int, 0444);
+MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
+static int shutdown_secs;
module_param(shutdown_secs, int, 0444);
-MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable.");
+MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), <= zero to disable.");
+static int stall_cpu;
module_param(stall_cpu, int, 0444);
MODULE_PARM_DESC(stall_cpu, "Stall duration (s), zero to disable.");
+static int stall_cpu_holdoff = 10;
module_param(stall_cpu_holdoff, int, 0444);
MODULE_PARM_DESC(stall_cpu_holdoff, "Time to wait before starting stall (s).");
+static int stat_interval = 60;
+module_param(stat_interval, int, 0644);
+MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
+static int stutter = 5;
+module_param(stutter, int, 0444);
+MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
+static int test_boost = 1;
module_param(test_boost, int, 0444);
MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
-module_param(test_boost_interval, int, 0444);
-MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds.");
+static int test_boost_duration = 4;
module_param(test_boost_duration, int, 0444);
MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds.");
+static int test_boost_interval = 7;
+module_param(test_boost_interval, int, 0444);
+MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds.");
+static bool test_no_idle_hz = true;
+module_param(test_no_idle_hz, bool, 0444);
+MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
+static char *torture_type = "rcu";
module_param(torture_type, charp, 0444);
-MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
+MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
+static bool verbose;
+module_param(verbose, bool, 0444);
+MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
#define TORTURE_FLAG "-torture:"
#define PRINTK_STRING(s) \
@@ -267,7 +273,7 @@ rcutorture_shutdown_notify(struct notifier_block *unused1,
* Absorb kthreads into a kernel function that won't return, so that
* they won't ever access module text or data again.
*/
-static void rcutorture_shutdown_absorb(char *title)
+static void rcutorture_shutdown_absorb(const char *title)
{
if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
pr_notice(
@@ -337,7 +343,7 @@ rcu_random(struct rcu_random_state *rrsp)
}
static void
-rcu_stutter_wait(char *title)
+rcu_stutter_wait(const char *title)
{
while (stutter_pause_test || !rcutorture_runnable) {
if (rcutorture_runnable)
@@ -360,13 +366,14 @@ struct rcu_torture_ops {
int (*completed)(void);
void (*deferred_free)(struct rcu_torture *p);
void (*sync)(void);
+ void (*exp_sync)(void);
void (*call)(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
void (*cb_barrier)(void);
void (*fqs)(void);
int (*stats)(char *page);
int irq_capable;
int can_boost;
- char *name;
+ const char *name;
};
static struct rcu_torture_ops *cur_ops;
@@ -443,81 +450,27 @@ static void rcu_torture_deferred_free(struct rcu_torture *p)
call_rcu(&p->rtort_rcu, rcu_torture_cb);
}
-static struct rcu_torture_ops rcu_ops = {
- .init = NULL,
- .readlock = rcu_torture_read_lock,
- .read_delay = rcu_read_delay,
- .readunlock = rcu_torture_read_unlock,
- .completed = rcu_torture_completed,
- .deferred_free = rcu_torture_deferred_free,
- .sync = synchronize_rcu,
- .call = call_rcu,
- .cb_barrier = rcu_barrier,
- .fqs = rcu_force_quiescent_state,
- .stats = NULL,
- .irq_capable = 1,
- .can_boost = rcu_can_boost(),
- .name = "rcu"
-};
-
-static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
-{
- int i;
- struct rcu_torture *rp;
- struct rcu_torture *rp1;
-
- cur_ops->sync();
- list_add(&p->rtort_free, &rcu_torture_removed);
- list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
- i = rp->rtort_pipe_count;
- if (i > RCU_TORTURE_PIPE_LEN)
- i = RCU_TORTURE_PIPE_LEN;
- atomic_inc(&rcu_torture_wcount[i]);
- if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
- rp->rtort_mbtest = 0;
- list_del(&rp->rtort_free);
- rcu_torture_free(rp);
- }
- }
-}
-
static void rcu_sync_torture_init(void)
{
INIT_LIST_HEAD(&rcu_torture_removed);
}
-static struct rcu_torture_ops rcu_sync_ops = {
+static struct rcu_torture_ops rcu_ops = {
.init = rcu_sync_torture_init,
.readlock = rcu_torture_read_lock,
.read_delay = rcu_read_delay,
.readunlock = rcu_torture_read_unlock,
.completed = rcu_torture_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
+ .deferred_free = rcu_torture_deferred_free,
.sync = synchronize_rcu,
- .call = NULL,
- .cb_barrier = NULL,
- .fqs = rcu_force_quiescent_state,
- .stats = NULL,
- .irq_capable = 1,
- .can_boost = rcu_can_boost(),
- .name = "rcu_sync"
-};
-
-static struct rcu_torture_ops rcu_expedited_ops = {
- .init = rcu_sync_torture_init,
- .readlock = rcu_torture_read_lock,
- .read_delay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_torture_read_unlock,
- .completed = rcu_no_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
- .sync = synchronize_rcu_expedited,
- .call = NULL,
- .cb_barrier = NULL,
+ .exp_sync = synchronize_rcu_expedited,
+ .call = call_rcu,
+ .cb_barrier = rcu_barrier,
.fqs = rcu_force_quiescent_state,
.stats = NULL,
.irq_capable = 1,
.can_boost = rcu_can_boost(),
- .name = "rcu_expedited"
+ .name = "rcu"
};
/*
@@ -546,13 +499,14 @@ static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
}
static struct rcu_torture_ops rcu_bh_ops = {
- .init = NULL,
+ .init = rcu_sync_torture_init,
.readlock = rcu_bh_torture_read_lock,
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
.readunlock = rcu_bh_torture_read_unlock,
.completed = rcu_bh_torture_completed,
.deferred_free = rcu_bh_torture_deferred_free,
.sync = synchronize_rcu_bh,
+ .exp_sync = synchronize_rcu_bh_expedited,
.call = call_rcu_bh,
.cb_barrier = rcu_barrier_bh,
.fqs = rcu_bh_force_quiescent_state,
@@ -561,38 +515,6 @@ static struct rcu_torture_ops rcu_bh_ops = {
.name = "rcu_bh"
};
-static struct rcu_torture_ops rcu_bh_sync_ops = {
- .init = rcu_sync_torture_init,
- .readlock = rcu_bh_torture_read_lock,
- .read_delay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_bh_torture_read_unlock,
- .completed = rcu_bh_torture_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
- .sync = synchronize_rcu_bh,
- .call = NULL,
- .cb_barrier = NULL,
- .fqs = rcu_bh_force_quiescent_state,
- .stats = NULL,
- .irq_capable = 1,
- .name = "rcu_bh_sync"
-};
-
-static struct rcu_torture_ops rcu_bh_expedited_ops = {
- .init = rcu_sync_torture_init,
- .readlock = rcu_bh_torture_read_lock,
- .read_delay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_bh_torture_read_unlock,
- .completed = rcu_bh_torture_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
- .sync = synchronize_rcu_bh_expedited,
- .call = NULL,
- .cb_barrier = NULL,
- .fqs = rcu_bh_force_quiescent_state,
- .stats = NULL,
- .irq_capable = 1,
- .name = "rcu_bh_expedited"
-};
-
/*
* Definitions for srcu torture testing.
*/
@@ -667,6 +589,11 @@ static int srcu_torture_stats(char *page)
return cnt;
}
+static void srcu_torture_synchronize_expedited(void)
+{
+ synchronize_srcu_expedited(&srcu_ctl);
+}
+
static struct rcu_torture_ops srcu_ops = {
.init = rcu_sync_torture_init,
.readlock = srcu_torture_read_lock,
@@ -675,45 +602,13 @@ static struct rcu_torture_ops srcu_ops = {
.completed = srcu_torture_completed,
.deferred_free = srcu_torture_deferred_free,
.sync = srcu_torture_synchronize,
+ .exp_sync = srcu_torture_synchronize_expedited,
.call = srcu_torture_call,
.cb_barrier = srcu_torture_barrier,
.stats = srcu_torture_stats,
.name = "srcu"
};
-static struct rcu_torture_ops srcu_sync_ops = {
- .init = rcu_sync_torture_init,
- .readlock = srcu_torture_read_lock,
- .read_delay = srcu_read_delay,
- .readunlock = srcu_torture_read_unlock,
- .completed = srcu_torture_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
- .sync = srcu_torture_synchronize,
- .call = NULL,
- .cb_barrier = NULL,
- .stats = srcu_torture_stats,
- .name = "srcu_sync"
-};
-
-static void srcu_torture_synchronize_expedited(void)
-{
- synchronize_srcu_expedited(&srcu_ctl);
-}
-
-static struct rcu_torture_ops srcu_expedited_ops = {
- .init = rcu_sync_torture_init,
- .readlock = srcu_torture_read_lock,
- .read_delay = srcu_read_delay,
- .readunlock = srcu_torture_read_unlock,
- .completed = srcu_torture_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
- .sync = srcu_torture_synchronize_expedited,
- .call = NULL,
- .cb_barrier = NULL,
- .stats = srcu_torture_stats,
- .name = "srcu_expedited"
-};
-
/*
* Definitions for sched torture testing.
*/
@@ -742,6 +637,8 @@ static struct rcu_torture_ops sched_ops = {
.completed = rcu_no_completed,
.deferred_free = rcu_sched_torture_deferred_free,
.sync = synchronize_sched,
+ .exp_sync = synchronize_sched_expedited,
+ .call = call_rcu_sched,
.cb_barrier = rcu_barrier_sched,
.fqs = rcu_sched_force_quiescent_state,
.stats = NULL,
@@ -749,35 +646,6 @@ static struct rcu_torture_ops sched_ops = {
.name = "sched"
};
-static struct rcu_torture_ops sched_sync_ops = {
- .init = rcu_sync_torture_init,
- .readlock = sched_torture_read_lock,
- .read_delay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = sched_torture_read_unlock,
- .completed = rcu_no_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
- .sync = synchronize_sched,
- .cb_barrier = NULL,
- .fqs = rcu_sched_force_quiescent_state,
- .stats = NULL,
- .name = "sched_sync"
-};
-
-static struct rcu_torture_ops sched_expedited_ops = {
- .init = rcu_sync_torture_init,
- .readlock = sched_torture_read_lock,
- .read_delay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = sched_torture_read_unlock,
- .completed = rcu_no_completed,
- .deferred_free = rcu_sync_torture_deferred_free,
- .sync = synchronize_sched_expedited,
- .cb_barrier = NULL,
- .fqs = rcu_sched_force_quiescent_state,
- .stats = NULL,
- .irq_capable = 1,
- .name = "sched_expedited"
-};
-
/*
* RCU torture priority-boost testing. Runs one real-time thread per
* CPU for moderate bursts, repeatedly registering RCU callbacks and
@@ -927,9 +795,10 @@ rcu_torture_fqs(void *arg)
static int
rcu_torture_writer(void *arg)
{
+ bool exp;
int i;
- long oldbatch = rcu_batches_completed();
struct rcu_torture *rp;
+ struct rcu_torture *rp1;
struct rcu_torture *old_rp;
static DEFINE_RCU_RANDOM(rand);
@@ -954,10 +823,33 @@ rcu_torture_writer(void *arg)
i = RCU_TORTURE_PIPE_LEN;
atomic_inc(&rcu_torture_wcount[i]);
old_rp->rtort_pipe_count++;
- cur_ops->deferred_free(old_rp);
+ if (gp_normal == gp_exp)
+ exp = !!(rcu_random(&rand) & 0x80);
+ else
+ exp = gp_exp;
+ if (!exp) {
+ cur_ops->deferred_free(old_rp);
+ } else {
+ cur_ops->exp_sync();
+ list_add(&old_rp->rtort_free,
+ &rcu_torture_removed);
+ list_for_each_entry_safe(rp, rp1,
+ &rcu_torture_removed,
+ rtort_free) {
+ i = rp->rtort_pipe_count;
+ if (i > RCU_TORTURE_PIPE_LEN)
+ i = RCU_TORTURE_PIPE_LEN;
+ atomic_inc(&rcu_torture_wcount[i]);
+ if (++rp->rtort_pipe_count >=
+ RCU_TORTURE_PIPE_LEN) {
+ rp->rtort_mbtest = 0;
+ list_del(&rp->rtort_free);
+ rcu_torture_free(rp);
+ }
+ }
+ }
}
rcutorture_record_progress(++rcu_torture_current_version);
- oldbatch = cur_ops->completed();
rcu_stutter_wait("rcu_torture_writer");
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
@@ -983,10 +875,18 @@ rcu_torture_fakewriter(void *arg)
schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
udelay(rcu_random(&rand) & 0x3ff);
if (cur_ops->cb_barrier != NULL &&
- rcu_random(&rand) % (nfakewriters * 8) == 0)
+ rcu_random(&rand) % (nfakewriters * 8) == 0) {
cur_ops->cb_barrier();
- else
+ } else if (gp_normal == gp_exp) {
+ if (rcu_random(&rand) & 0x80)
+ cur_ops->sync();
+ else
+ cur_ops->exp_sync();
+ } else if (gp_normal) {
cur_ops->sync();
+ } else {
+ cur_ops->exp_sync();
+ }
rcu_stutter_wait("rcu_torture_fakewriter");
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
@@ -1364,7 +1264,7 @@ rcu_torture_stutter(void *arg)
}
static inline void
-rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, char *tag)
+rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
{
pr_alert("%s" TORTURE_FLAG
"--- %s: nreaders=%d nfakewriters=%d "
@@ -1534,7 +1434,13 @@ rcu_torture_onoff(void *arg)
torture_type, cpu);
starttime = jiffies;
n_online_attempts++;
- if (cpu_up(cpu) == 0) {
+ ret = cpu_up(cpu);
+ if (ret) {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "rcu_torture_onoff task: online %d failed: errno %d\n",
+ torture_type, cpu, ret);
+ } else {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"rcu_torture_onoff task: onlined %d\n",
@@ -1934,6 +1840,62 @@ rcu_torture_cleanup(void)
rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
}
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+static void rcu_torture_leak_cb(struct rcu_head *rhp)
+{
+}
+
+static void rcu_torture_err_cb(struct rcu_head *rhp)
+{
+ /*
+ * This -might- happen due to race conditions, but is unlikely.
+ * The scenario that leads to this happening is that the
+ * first of the pair of duplicate callbacks is queued,
+ * someone else starts a grace period that includes that
+ * callback, then the second of the pair must wait for the
+ * next grace period. Unlikely, but can happen. If it
+ * does happen, the debug-objects subsystem won't have splatted.
+ */
+ pr_alert("rcutorture: duplicated callback was invoked.\n");
+}
+#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+
+/*
+ * Verify that double-free causes debug-objects to complain, but only
+ * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
+ * cannot be carried out.
+ */
+static void rcu_test_debug_objects(void)
+{
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+ struct rcu_head rh1;
+ struct rcu_head rh2;
+
+ init_rcu_head_on_stack(&rh1);
+ init_rcu_head_on_stack(&rh2);
+ pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
+
+ /* Try to queue the rh2 pair of callbacks for the same grace period. */
+ preempt_disable(); /* Prevent preemption from interrupting test. */
+ rcu_read_lock(); /* Make it impossible to finish a grace period. */
+ call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
+ local_irq_disable(); /* Make it harder to start a new grace period. */
+ call_rcu(&rh2, rcu_torture_leak_cb);
+ call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
+ local_irq_enable();
+ rcu_read_unlock();
+ preempt_enable();
+
+ /* Wait for them all to get done so we can safely return. */
+ rcu_barrier();
+ pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
+ destroy_rcu_head_on_stack(&rh1);
+ destroy_rcu_head_on_stack(&rh2);
+#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+ pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
+#endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+}
+
static int __init
rcu_torture_init(void)
{
@@ -1941,11 +1903,9 @@ rcu_torture_init(void)
int cpu;
int firsterr = 0;
int retval;
- static struct rcu_torture_ops *torture_ops[] =
- { &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops,
- &rcu_bh_ops, &rcu_bh_sync_ops, &rcu_bh_expedited_ops,
- &srcu_ops, &srcu_sync_ops, &srcu_expedited_ops,
- &sched_ops, &sched_sync_ops, &sched_expedited_ops, };
+ static struct rcu_torture_ops *torture_ops[] = {
+ &rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops,
+ };
mutex_lock(&fullstop_mutex);
@@ -2163,6 +2123,8 @@ rcu_torture_init(void)
firsterr = retval;
goto unwind;
}
+ if (object_debug)
+ rcu_test_debug_objects();
rcutorture_record_test_transition();
mutex_unlock(&fullstop_mutex);
return 0;
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 068de3a93606..32618b3fe4e6 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -53,18 +53,38 @@
#include <linux/delay.h>
#include <linux/stop_machine.h>
#include <linux/random.h>
+#include <linux/ftrace_event.h>
+#include <linux/suspend.h>
#include "rcutree.h"
#include <trace/events/rcu.h>
#include "rcu.h"
+/*
+ * Strings used in tracepoints need to be exported via the
+ * tracing system such that tools like perf and trace-cmd can
+ * translate the string address pointers to actual text.
+ */
+#define TPS(x) tracepoint_string(x)
+
/* Data structures. */
static struct lock_class_key rcu_node_class[RCU_NUM_LVLS];
static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
-#define RCU_STATE_INITIALIZER(sname, sabbr, cr) { \
+/*
+ * In order to export the rcu_state name to the tracing tools, it
+ * needs to be added in the __tracepoint_string section.
+ * This requires defining a separate variable tp_<sname>_varname
+ * that points to the string being used, and this will allow
+ * the tracing userspace tools to be able to decipher the string
+ * address to the matching string.
+ */
+#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
+static char sname##_varname[] = #sname; \
+static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname; \
+struct rcu_state sname##_state = { \
.level = { &sname##_state.node[0] }, \
.call = cr, \
.fqs_state = RCU_GP_IDLE, \
@@ -75,16 +95,13 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
.orphan_donetail = &sname##_state.orphan_donelist, \
.barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \
.onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
- .name = #sname, \
+ .name = sname##_varname, \
.abbr = sabbr, \
-}
-
-struct rcu_state rcu_sched_state =
- RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
-DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
+}; \
+DEFINE_PER_CPU(struct rcu_data, sname##_data)
-struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
-DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
+RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
+RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
static struct rcu_state *rcu_state;
LIST_HEAD(rcu_struct_flavors);
@@ -178,7 +195,7 @@ void rcu_sched_qs(int cpu)
struct rcu_data *rdp = &per_cpu(rcu_sched_data, cpu);
if (rdp->passed_quiesce == 0)
- trace_rcu_grace_period("rcu_sched", rdp->gpnum, "cpuqs");
+ trace_rcu_grace_period(TPS("rcu_sched"), rdp->gpnum, TPS("cpuqs"));
rdp->passed_quiesce = 1;
}
@@ -187,7 +204,7 @@ void rcu_bh_qs(int cpu)
struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
if (rdp->passed_quiesce == 0)
- trace_rcu_grace_period("rcu_bh", rdp->gpnum, "cpuqs");
+ trace_rcu_grace_period(TPS("rcu_bh"), rdp->gpnum, TPS("cpuqs"));
rdp->passed_quiesce = 1;
}
@@ -198,16 +215,20 @@ void rcu_bh_qs(int cpu)
*/
void rcu_note_context_switch(int cpu)
{
- trace_rcu_utilization("Start context switch");
+ trace_rcu_utilization(TPS("Start context switch"));
rcu_sched_qs(cpu);
rcu_preempt_note_context_switch(cpu);
- trace_rcu_utilization("End context switch");
+ trace_rcu_utilization(TPS("End context switch"));
}
EXPORT_SYMBOL_GPL(rcu_note_context_switch);
DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
.dynticks_nesting = DYNTICK_TASK_EXIT_IDLE,
.dynticks = ATOMIC_INIT(1),
+#ifdef CONFIG_NO_HZ_FULL_SYSIDLE
+ .dynticks_idle_nesting = DYNTICK_TASK_NEST_VALUE,
+ .dynticks_idle = ATOMIC_INIT(1),
+#endif /* #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
};
static long blimit = 10; /* Maximum callbacks per rcu_do_batch. */
@@ -226,7 +247,10 @@ module_param(jiffies_till_next_fqs, ulong, 0644);
static void rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp,
struct rcu_data *rdp);
-static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *));
+static void force_qs_rnp(struct rcu_state *rsp,
+ int (*f)(struct rcu_data *rsp, bool *isidle,
+ unsigned long *maxj),
+ bool *isidle, unsigned long *maxj);
static void force_quiescent_state(struct rcu_state *rsp);
static int rcu_pending(int cpu);
@@ -345,11 +369,11 @@ static struct rcu_node *rcu_get_root(struct rcu_state *rsp)
static void rcu_eqs_enter_common(struct rcu_dynticks *rdtp, long long oldval,
bool user)
{
- trace_rcu_dyntick("Start", oldval, rdtp->dynticks_nesting);
+ trace_rcu_dyntick(TPS("Start"), oldval, rdtp->dynticks_nesting);
if (!user && !is_idle_task(current)) {
struct task_struct *idle = idle_task(smp_processor_id());
- trace_rcu_dyntick("Error on entry: not idle task", oldval, 0);
+ trace_rcu_dyntick(TPS("Error on entry: not idle task"), oldval, 0);
ftrace_dump(DUMP_ORIG);
WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
current->pid, current->comm,
@@ -411,6 +435,7 @@ void rcu_idle_enter(void)
local_irq_save(flags);
rcu_eqs_enter(false);
+ rcu_sysidle_enter(&__get_cpu_var(rcu_dynticks), 0);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(rcu_idle_enter);
@@ -428,27 +453,6 @@ void rcu_user_enter(void)
{
rcu_eqs_enter(1);
}
-
-/**
- * rcu_user_enter_after_irq - inform RCU that we are going to resume userspace
- * after the current irq returns.
- *
- * This is similar to rcu_user_enter() but in the context of a non-nesting
- * irq. After this call, RCU enters into idle mode when the interrupt
- * returns.
- */
-void rcu_user_enter_after_irq(void)
-{
- unsigned long flags;
- struct rcu_dynticks *rdtp;
-
- local_irq_save(flags);
- rdtp = &__get_cpu_var(rcu_dynticks);
- /* Ensure this irq is interrupting a non-idle RCU state. */
- WARN_ON_ONCE(!(rdtp->dynticks_nesting & DYNTICK_TASK_MASK));
- rdtp->dynticks_nesting = 1;
- local_irq_restore(flags);
-}
#endif /* CONFIG_RCU_USER_QS */
/**
@@ -479,9 +483,10 @@ void rcu_irq_exit(void)
rdtp->dynticks_nesting--;
WARN_ON_ONCE(rdtp->dynticks_nesting < 0);
if (rdtp->dynticks_nesting)
- trace_rcu_dyntick("--=", oldval, rdtp->dynticks_nesting);
+ trace_rcu_dyntick(TPS("--="), oldval, rdtp->dynticks_nesting);
else
rcu_eqs_enter_common(rdtp, oldval, true);
+ rcu_sysidle_enter(rdtp, 1);
local_irq_restore(flags);
}
@@ -501,11 +506,11 @@ static void rcu_eqs_exit_common(struct rcu_dynticks *rdtp, long long oldval,
smp_mb__after_atomic_inc(); /* See above. */
WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
rcu_cleanup_after_idle(smp_processor_id());
- trace_rcu_dyntick("End", oldval, rdtp->dynticks_nesting);
+ trace_rcu_dyntick(TPS("End"), oldval, rdtp->dynticks_nesting);
if (!user && !is_idle_task(current)) {
struct task_struct *idle = idle_task(smp_processor_id());
- trace_rcu_dyntick("Error on exit: not idle task",
+ trace_rcu_dyntick(TPS("Error on exit: not idle task"),
oldval, rdtp->dynticks_nesting);
ftrace_dump(DUMP_ORIG);
WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
@@ -550,6 +555,7 @@ void rcu_idle_exit(void)
local_irq_save(flags);
rcu_eqs_exit(false);
+ rcu_sysidle_exit(&__get_cpu_var(rcu_dynticks), 0);
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(rcu_idle_exit);
@@ -565,28 +571,6 @@ void rcu_user_exit(void)
{
rcu_eqs_exit(1);
}
-
-/**
- * rcu_user_exit_after_irq - inform RCU that we won't resume to userspace
- * idle mode after the current non-nesting irq returns.
- *
- * This is similar to rcu_user_exit() but in the context of an irq.
- * This is called when the irq has interrupted a userspace RCU idle mode
- * context. When the current non-nesting interrupt returns after this call,
- * the CPU won't restore the RCU idle mode.
- */
-void rcu_user_exit_after_irq(void)
-{
- unsigned long flags;
- struct rcu_dynticks *rdtp;
-
- local_irq_save(flags);
- rdtp = &__get_cpu_var(rcu_dynticks);
- /* Ensure we are interrupting an RCU idle mode. */
- WARN_ON_ONCE(rdtp->dynticks_nesting & DYNTICK_TASK_NEST_MASK);
- rdtp->dynticks_nesting += DYNTICK_TASK_EXIT_IDLE;
- local_irq_restore(flags);
-}
#endif /* CONFIG_RCU_USER_QS */
/**
@@ -620,9 +604,10 @@ void rcu_irq_enter(void)
rdtp->dynticks_nesting++;
WARN_ON_ONCE(rdtp->dynticks_nesting == 0);
if (oldval)
- trace_rcu_dyntick("++=", oldval, rdtp->dynticks_nesting);
+ trace_rcu_dyntick(TPS("++="), oldval, rdtp->dynticks_nesting);
else
rcu_eqs_exit_common(rdtp, oldval, true);
+ rcu_sysidle_exit(rdtp, 1);
local_irq_restore(flags);
}
@@ -746,9 +731,11 @@ static int rcu_is_cpu_rrupt_from_idle(void)
* credit them with an implicit quiescent state. Return 1 if this CPU
* is in dynticks idle mode, which is an extended quiescent state.
*/
-static int dyntick_save_progress_counter(struct rcu_data *rdp)
+static int dyntick_save_progress_counter(struct rcu_data *rdp,
+ bool *isidle, unsigned long *maxj)
{
rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks);
+ rcu_sysidle_check_cpu(rdp, isidle, maxj);
return (rdp->dynticks_snap & 0x1) == 0;
}
@@ -758,7 +745,8 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
* idle state since the last call to dyntick_save_progress_counter()
* for this same CPU, or by virtue of having been offline.
*/
-static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
+static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
+ bool *isidle, unsigned long *maxj)
{
unsigned int curr;
unsigned int snap;
@@ -775,7 +763,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
* of the current RCU grace period.
*/
if ((curr & 0x1) == 0 || UINT_CMP_GE(curr, snap + 2)) {
- trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, "dti");
+ trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti"));
rdp->dynticks_fqs++;
return 1;
}
@@ -795,7 +783,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
return 0; /* Grace period is not old enough. */
barrier();
if (cpu_is_offline(rdp->cpu)) {
- trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, "ofl");
+ trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("ofl"));
rdp->offline_fqs++;
return 1;
}
@@ -1032,7 +1020,7 @@ static unsigned long rcu_cbs_completed(struct rcu_state *rsp,
* rcu_nocb_wait_gp().
*/
static void trace_rcu_future_gp(struct rcu_node *rnp, struct rcu_data *rdp,
- unsigned long c, char *s)
+ unsigned long c, const char *s)
{
trace_rcu_future_grace_period(rdp->rsp->name, rnp->gpnum,
rnp->completed, c, rnp->level,
@@ -1058,9 +1046,9 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp)
* grace period is already marked as needed, return to the caller.
*/
c = rcu_cbs_completed(rdp->rsp, rnp);
- trace_rcu_future_gp(rnp, rdp, c, "Startleaf");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("Startleaf"));
if (rnp->need_future_gp[c & 0x1]) {
- trace_rcu_future_gp(rnp, rdp, c, "Prestartleaf");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("Prestartleaf"));
return c;
}
@@ -1074,7 +1062,7 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp)
if (rnp->gpnum != rnp->completed ||
ACCESS_ONCE(rnp->gpnum) != ACCESS_ONCE(rnp->completed)) {
rnp->need_future_gp[c & 0x1]++;
- trace_rcu_future_gp(rnp, rdp, c, "Startedleaf");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("Startedleaf"));
return c;
}
@@ -1102,7 +1090,7 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp)
* recorded, trace and leave.
*/
if (rnp_root->need_future_gp[c & 0x1]) {
- trace_rcu_future_gp(rnp, rdp, c, "Prestartedroot");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("Prestartedroot"));
goto unlock_out;
}
@@ -1111,9 +1099,9 @@ rcu_start_future_gp(struct rcu_node *rnp, struct rcu_data *rdp)
/* If a grace period is not already in progress, start one. */
if (rnp_root->gpnum != rnp_root->completed) {
- trace_rcu_future_gp(rnp, rdp, c, "Startedleafroot");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("Startedleafroot"));
} else {
- trace_rcu_future_gp(rnp, rdp, c, "Startedroot");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("Startedroot"));
rcu_start_gp_advanced(rdp->rsp, rnp_root, rdp);
}
unlock_out:
@@ -1137,7 +1125,8 @@ static int rcu_future_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
rcu_nocb_gp_cleanup(rsp, rnp);
rnp->need_future_gp[c & 0x1] = 0;
needmore = rnp->need_future_gp[(c + 1) & 0x1];
- trace_rcu_future_gp(rnp, rdp, c, needmore ? "CleanupMore" : "Cleanup");
+ trace_rcu_future_gp(rnp, rdp, c,
+ needmore ? TPS("CleanupMore") : TPS("Cleanup"));
return needmore;
}
@@ -1205,9 +1194,9 @@ static void rcu_accelerate_cbs(struct rcu_state *rsp, struct rcu_node *rnp,
/* Trace depending on how much we were able to accelerate. */
if (!*rdp->nxttail[RCU_WAIT_TAIL])
- trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccWaitCB");
+ trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("AccWaitCB"));
else
- trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccReadyCB");
+ trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("AccReadyCB"));
}
/*
@@ -1273,7 +1262,7 @@ static void __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, struc
/* Remember that we saw this grace-period completion. */
rdp->completed = rnp->completed;
- trace_rcu_grace_period(rsp->name, rdp->gpnum, "cpuend");
+ trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuend"));
}
if (rdp->gpnum != rnp->gpnum) {
@@ -1283,7 +1272,7 @@ static void __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, struc
* go looking for one.
*/
rdp->gpnum = rnp->gpnum;
- trace_rcu_grace_period(rsp->name, rdp->gpnum, "cpustart");
+ trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpustart"));
rdp->passed_quiesce = 0;
rdp->qs_pending = !!(rnp->qsmask & rdp->grpmask);
zero_cpu_stall_ticks(rdp);
@@ -1315,6 +1304,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
struct rcu_data *rdp;
struct rcu_node *rnp = rcu_get_root(rsp);
+ rcu_bind_gp_kthread();
raw_spin_lock_irq(&rnp->lock);
rsp->gp_flags = 0; /* Clear all flags: New grace period. */
@@ -1326,7 +1316,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
/* Advance to a new grace period and initialize state. */
rsp->gpnum++;
- trace_rcu_grace_period(rsp->name, rsp->gpnum, "start");
+ trace_rcu_grace_period(rsp->name, rsp->gpnum, TPS("start"));
record_gp_stall_check_time(rsp);
raw_spin_unlock_irq(&rnp->lock);
@@ -1379,16 +1369,25 @@ static int rcu_gp_init(struct rcu_state *rsp)
int rcu_gp_fqs(struct rcu_state *rsp, int fqs_state_in)
{
int fqs_state = fqs_state_in;
+ bool isidle = false;
+ unsigned long maxj;
struct rcu_node *rnp = rcu_get_root(rsp);
rsp->n_force_qs++;
if (fqs_state == RCU_SAVE_DYNTICK) {
/* Collect dyntick-idle snapshots. */
- force_qs_rnp(rsp, dyntick_save_progress_counter);
+ if (is_sysidle_rcu_state(rsp)) {
+ isidle = 1;
+ maxj = jiffies - ULONG_MAX / 4;
+ }
+ force_qs_rnp(rsp, dyntick_save_progress_counter,
+ &isidle, &maxj);
+ rcu_sysidle_report_gp(rsp, isidle, maxj);
fqs_state = RCU_FORCE_QS;
} else {
/* Handle dyntick-idle and offline CPUs. */
- force_qs_rnp(rsp, rcu_implicit_dynticks_qs);
+ isidle = 0;
+ force_qs_rnp(rsp, rcu_implicit_dynticks_qs, &isidle, &maxj);
}
/* Clear flag to prevent immediate re-entry. */
if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
@@ -1448,7 +1447,7 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
rcu_nocb_gp_set(rnp, nocb);
rsp->completed = rsp->gpnum; /* Declare grace period done. */
- trace_rcu_grace_period(rsp->name, rsp->completed, "end");
+ trace_rcu_grace_period(rsp->name, rsp->completed, TPS("end"));
rsp->fqs_state = RCU_GP_IDLE;
rdp = this_cpu_ptr(rsp->rda);
rcu_advance_cbs(rsp, rnp, rdp); /* Reduce false positives below. */
@@ -1558,10 +1557,12 @@ rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp,
/*
* We can't do wakeups while holding the rnp->lock, as that
- * could cause possible deadlocks with the rq->lock. Deter
- * the wakeup to interrupt context.
+ * could cause possible deadlocks with the rq->lock. Defer
+ * the wakeup to interrupt context. And don't bother waking
+ * up the running kthread.
*/
- irq_work_queue(&rsp->wakeup_work);
+ if (current != rsp->gp_kthread)
+ irq_work_queue(&rsp->wakeup_work);
}
/*
@@ -1857,7 +1858,7 @@ static void rcu_cleanup_dying_cpu(struct rcu_state *rsp)
RCU_TRACE(mask = rdp->grpmask);
trace_rcu_grace_period(rsp->name,
rnp->gpnum + 1 - !!(rnp->qsmask & mask),
- "cpuofl");
+ TPS("cpuofl"));
}
/*
@@ -2044,7 +2045,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
*/
void rcu_check_callbacks(int cpu, int user)
{
- trace_rcu_utilization("Start scheduler-tick");
+ trace_rcu_utilization(TPS("Start scheduler-tick"));
increment_cpu_stall_ticks();
if (user || rcu_is_cpu_rrupt_from_idle()) {
@@ -2077,7 +2078,7 @@ void rcu_check_callbacks(int cpu, int user)
rcu_preempt_check_callbacks(cpu);
if (rcu_pending(cpu))
invoke_rcu_core();
- trace_rcu_utilization("End scheduler-tick");
+ trace_rcu_utilization(TPS("End scheduler-tick"));
}
/*
@@ -2087,7 +2088,10 @@ void rcu_check_callbacks(int cpu, int user)
*
* The caller must have suppressed start of new grace periods.
*/
-static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *))
+static void force_qs_rnp(struct rcu_state *rsp,
+ int (*f)(struct rcu_data *rsp, bool *isidle,
+ unsigned long *maxj),
+ bool *isidle, unsigned long *maxj)
{
unsigned long bit;
int cpu;
@@ -2110,9 +2114,12 @@ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *))
cpu = rnp->grplo;
bit = 1;
for (; cpu <= rnp->grphi; cpu++, bit <<= 1) {
- if ((rnp->qsmask & bit) != 0 &&
- f(per_cpu_ptr(rsp->rda, cpu)))
- mask |= bit;
+ if ((rnp->qsmask & bit) != 0) {
+ if ((rnp->qsmaskinit & bit) != 0)
+ *isidle = 0;
+ if (f(per_cpu_ptr(rsp->rda, cpu), isidle, maxj))
+ mask |= bit;
+ }
}
if (mask != 0) {
@@ -2208,10 +2215,10 @@ static void rcu_process_callbacks(struct softirq_action *unused)
if (cpu_is_offline(smp_processor_id()))
return;
- trace_rcu_utilization("Start RCU core");
+ trace_rcu_utilization(TPS("Start RCU core"));
for_each_rcu_flavor(rsp)
__rcu_process_callbacks(rsp);
- trace_rcu_utilization("End RCU core");
+ trace_rcu_utilization(TPS("End RCU core"));
}
/*
@@ -2287,6 +2294,13 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,
}
/*
+ * RCU callback function to leak a callback.
+ */
+static void rcu_leak_callback(struct rcu_head *rhp)
+{
+}
+
+/*
* Helper function for call_rcu() and friends. The cpu argument will
* normally be -1, indicating "currently running CPU". It may specify
* a CPU only if that CPU is a no-CBs CPU. Currently, only _rcu_barrier()
@@ -2300,7 +2314,12 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
struct rcu_data *rdp;
WARN_ON_ONCE((unsigned long)head & 0x3); /* Misaligned rcu_head! */
- debug_rcu_head_queue(head);
+ if (debug_rcu_head_queue(head)) {
+ /* Probable double call_rcu(), so leak the callback. */
+ ACCESS_ONCE(head->func) = rcu_leak_callback;
+ WARN_ONCE(1, "__call_rcu(): Leaked duplicate callback\n");
+ return;
+ }
head->func = func;
head->next = NULL;
@@ -2720,7 +2739,7 @@ static int rcu_cpu_has_callbacks(int cpu, bool *all_lazy)
* Helper function for _rcu_barrier() tracing. If tracing is disabled,
* the compiler is expected to optimize this away.
*/
-static void _rcu_barrier_trace(struct rcu_state *rsp, char *s,
+static void _rcu_barrier_trace(struct rcu_state *rsp, const char *s,
int cpu, unsigned long done)
{
trace_rcu_barrier(rsp->name, s, cpu,
@@ -2785,9 +2804,20 @@ static void _rcu_barrier(struct rcu_state *rsp)
* transition. The "if" expression below therefore rounds the old
* value up to the next even number and adds two before comparing.
*/
- snap_done = ACCESS_ONCE(rsp->n_barrier_done);
+ snap_done = rsp->n_barrier_done;
_rcu_barrier_trace(rsp, "Check", -1, snap_done);
- if (ULONG_CMP_GE(snap_done, ((snap + 1) & ~0x1) + 2)) {
+
+ /*
+ * If the value in snap is odd, we needed to wait for the current
+ * rcu_barrier() to complete, then wait for the next one, in other
+ * words, we need the value of snap_done to be three larger than
+ * the value of snap. On the other hand, if the value in snap is
+ * even, we only had to wait for the next rcu_barrier() to complete,
+ * in other words, we need the value of snap_done to be only two
+ * greater than the value of snap. The "(snap + 3) & ~0x1" computes
+ * this for us (thank you, Linus!).
+ */
+ if (ULONG_CMP_GE(snap_done, (snap + 3) & ~0x1)) {
_rcu_barrier_trace(rsp, "EarlyExit", -1, snap_done);
smp_mb(); /* caller's subsequent code after above check. */
mutex_unlock(&rsp->barrier_mutex);
@@ -2930,6 +2960,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible)
rdp->blimit = blimit;
init_callback_list(rdp); /* Re-enable callbacks on this CPU. */
rdp->dynticks->dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
+ rcu_sysidle_init_percpu_data(rdp->dynticks);
atomic_set(&rdp->dynticks->dynticks,
(atomic_read(&rdp->dynticks->dynticks) & ~0x1) + 1);
raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
@@ -2952,7 +2983,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible)
rdp->completed = rnp->completed;
rdp->passed_quiesce = 0;
rdp->qs_pending = 0;
- trace_rcu_grace_period(rsp->name, rdp->gpnum, "cpuonl");
+ trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl"));
}
raw_spin_unlock(&rnp->lock); /* irqs already disabled. */
rnp = rnp->parent;
@@ -2982,7 +3013,7 @@ static int rcu_cpu_notify(struct notifier_block *self,
struct rcu_node *rnp = rdp->mynode;
struct rcu_state *rsp;
- trace_rcu_utilization("Start CPU hotplug");
+ trace_rcu_utilization(TPS("Start CPU hotplug"));
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
@@ -3011,7 +3042,26 @@ static int rcu_cpu_notify(struct notifier_block *self,
default:
break;
}
- trace_rcu_utilization("End CPU hotplug");
+ trace_rcu_utilization(TPS("End CPU hotplug"));
+ return NOTIFY_OK;
+}
+
+static int rcu_pm_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ switch (action) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_SUSPEND_PREPARE:
+ if (nr_cpu_ids <= 256) /* Expediting bad for large systems. */
+ rcu_expedited = 1;
+ break;
+ case PM_POST_HIBERNATION:
+ case PM_POST_SUSPEND:
+ rcu_expedited = 0;
+ break;
+ default:
+ break;
+ }
return NOTIFY_OK;
}
@@ -3256,6 +3306,7 @@ void __init rcu_init(void)
* or the scheduler are operational.
*/
cpu_notifier(rcu_cpu_notify, 0);
+ pm_notifier(rcu_pm_notify, 0);
for_each_online_cpu(cpu)
rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
}
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index b3832581043c..5f97eab602cd 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -88,6 +88,14 @@ struct rcu_dynticks {
/* Process level is worth LLONG_MAX/2. */
int dynticks_nmi_nesting; /* Track NMI nesting level. */
atomic_t dynticks; /* Even value for idle, else odd. */
+#ifdef CONFIG_NO_HZ_FULL_SYSIDLE
+ long long dynticks_idle_nesting;
+ /* irq/process nesting level from idle. */
+ atomic_t dynticks_idle; /* Even value for idle, else odd. */
+ /* "Idle" excludes userspace execution. */
+ unsigned long dynticks_idle_jiffies;
+ /* End of last non-NMI non-idle period. */
+#endif /* #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
#ifdef CONFIG_RCU_FAST_NO_HZ
bool all_lazy; /* Are all CPU's CBs lazy? */
unsigned long nonlazy_posted;
@@ -445,7 +453,7 @@ struct rcu_state {
/* for CPU stalls. */
unsigned long gp_max; /* Maximum GP duration in */
/* jiffies. */
- char *name; /* Name of structure. */
+ const char *name; /* Name of structure. */
char abbr; /* Abbreviated name. */
struct list_head flavors; /* List of RCU flavors. */
struct irq_work wakeup_work; /* Postponed wakeups */
@@ -545,6 +553,15 @@ static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp);
static void rcu_spawn_nocb_kthreads(struct rcu_state *rsp);
static void rcu_kick_nohz_cpu(int cpu);
static bool init_nocb_callback_list(struct rcu_data *rdp);
+static void rcu_sysidle_enter(struct rcu_dynticks *rdtp, int irq);
+static void rcu_sysidle_exit(struct rcu_dynticks *rdtp, int irq);
+static void rcu_sysidle_check_cpu(struct rcu_data *rdp, bool *isidle,
+ unsigned long *maxj);
+static bool is_sysidle_rcu_state(struct rcu_state *rsp);
+static void rcu_sysidle_report_gp(struct rcu_state *rsp, int isidle,
+ unsigned long maxj);
+static void rcu_bind_gp_kthread(void);
+static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp);
#endif /* #ifndef RCU_TREE_NONCORE */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 769e12e3151b..130c97b027f2 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -28,7 +28,7 @@
#include <linux/gfp.h>
#include <linux/oom.h>
#include <linux/smpboot.h>
-#include <linux/tick.h>
+#include "time/tick-internal.h"
#define RCU_KTHREAD_PRIO 1
@@ -110,9 +110,7 @@ static void __init rcu_bootup_announce_oddness(void)
#ifdef CONFIG_TREE_PREEMPT_RCU
-struct rcu_state rcu_preempt_state =
- RCU_STATE_INITIALIZER(rcu_preempt, 'p', call_rcu);
-DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data);
+RCU_STATE_INITIALIZER(rcu_preempt, 'p', call_rcu);
static struct rcu_state *rcu_state = &rcu_preempt_state;
static int rcu_preempted_readers_exp(struct rcu_node *rnp);
@@ -169,7 +167,7 @@ static void rcu_preempt_qs(int cpu)
struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu);
if (rdp->passed_quiesce == 0)
- trace_rcu_grace_period("rcu_preempt", rdp->gpnum, "cpuqs");
+ trace_rcu_grace_period(TPS("rcu_preempt"), rdp->gpnum, TPS("cpuqs"));
rdp->passed_quiesce = 1;
current->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
}
@@ -388,7 +386,7 @@ void rcu_read_unlock_special(struct task_struct *t)
np = rcu_next_node_entry(t, rnp);
list_del_init(&t->rcu_node_entry);
t->rcu_blocked_node = NULL;
- trace_rcu_unlock_preempted_task("rcu_preempt",
+ trace_rcu_unlock_preempted_task(TPS("rcu_preempt"),
rnp->gpnum, t->pid);
if (&t->rcu_node_entry == rnp->gp_tasks)
rnp->gp_tasks = np;
@@ -412,7 +410,7 @@ void rcu_read_unlock_special(struct task_struct *t)
*/
empty_exp_now = !rcu_preempted_readers_exp(rnp);
if (!empty && !rcu_preempt_blocked_readers_cgp(rnp)) {
- trace_rcu_quiescent_state_report("preempt_rcu",
+ trace_rcu_quiescent_state_report(TPS("preempt_rcu"),
rnp->gpnum,
0, rnp->qsmask,
rnp->level,
@@ -1250,12 +1248,12 @@ static int rcu_boost_kthread(void *arg)
int spincnt = 0;
int more2boost;
- trace_rcu_utilization("Start boost kthread@init");
+ trace_rcu_utilization(TPS("Start boost kthread@init"));
for (;;) {
rnp->boost_kthread_status = RCU_KTHREAD_WAITING;
- trace_rcu_utilization("End boost kthread@rcu_wait");
+ trace_rcu_utilization(TPS("End boost kthread@rcu_wait"));
rcu_wait(rnp->boost_tasks || rnp->exp_tasks);
- trace_rcu_utilization("Start boost kthread@rcu_wait");
+ trace_rcu_utilization(TPS("Start boost kthread@rcu_wait"));
rnp->boost_kthread_status = RCU_KTHREAD_RUNNING;
more2boost = rcu_boost(rnp);
if (more2boost)
@@ -1264,14 +1262,14 @@ static int rcu_boost_kthread(void *arg)
spincnt = 0;
if (spincnt > 10) {
rnp->boost_kthread_status = RCU_KTHREAD_YIELDING;
- trace_rcu_utilization("End boost kthread@rcu_yield");
+ trace_rcu_utilization(TPS("End boost kthread@rcu_yield"));
schedule_timeout_interruptible(2);
- trace_rcu_utilization("Start boost kthread@rcu_yield");
+ trace_rcu_utilization(TPS("Start boost kthread@rcu_yield"));
spincnt = 0;
}
}
/* NOTREACHED */
- trace_rcu_utilization("End boost kthread@notreached");
+ trace_rcu_utilization(TPS("End boost kthread@notreached"));
return 0;
}
@@ -1419,7 +1417,7 @@ static void rcu_cpu_kthread(unsigned int cpu)
int spincnt;
for (spincnt = 0; spincnt < 10; spincnt++) {
- trace_rcu_utilization("Start CPU kthread@rcu_wait");
+ trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
local_bh_disable();
*statusp = RCU_KTHREAD_RUNNING;
this_cpu_inc(rcu_cpu_kthread_loops);
@@ -1431,15 +1429,15 @@ static void rcu_cpu_kthread(unsigned int cpu)
rcu_kthread_do_work();
local_bh_enable();
if (*workp == 0) {
- trace_rcu_utilization("End CPU kthread@rcu_wait");
+ trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
*statusp = RCU_KTHREAD_WAITING;
return;
}
}
*statusp = RCU_KTHREAD_YIELDING;
- trace_rcu_utilization("Start CPU kthread@rcu_yield");
+ trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
schedule_timeout_interruptible(2);
- trace_rcu_utilization("End CPU kthread@rcu_yield");
+ trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
*statusp = RCU_KTHREAD_WAITING;
}
@@ -2202,7 +2200,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
* Wait for the grace period. Do so interruptibly to avoid messing
* up the load average.
*/
- trace_rcu_future_gp(rnp, rdp, c, "StartWait");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("StartWait"));
for (;;) {
wait_event_interruptible(
rnp->nocb_gp_wq[c & 0x1],
@@ -2210,9 +2208,9 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
if (likely(d))
break;
flush_signals(current);
- trace_rcu_future_gp(rnp, rdp, c, "ResumeWait");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("ResumeWait"));
}
- trace_rcu_future_gp(rnp, rdp, c, "EndWait");
+ trace_rcu_future_gp(rnp, rdp, c, TPS("EndWait"));
smp_mb(); /* Ensure that CB invocation happens after GP end. */
}
@@ -2375,3 +2373,425 @@ static void rcu_kick_nohz_cpu(int cpu)
smp_send_reschedule(cpu);
#endif /* #ifdef CONFIG_NO_HZ_FULL */
}
+
+
+#ifdef CONFIG_NO_HZ_FULL_SYSIDLE
+
+/*
+ * Define RCU flavor that holds sysidle state. This needs to be the
+ * most active flavor of RCU.
+ */
+#ifdef CONFIG_PREEMPT_RCU
+static struct rcu_state *rcu_sysidle_state = &rcu_preempt_state;
+#else /* #ifdef CONFIG_PREEMPT_RCU */
+static struct rcu_state *rcu_sysidle_state = &rcu_sched_state;
+#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
+
+static int full_sysidle_state; /* Current system-idle state. */
+#define RCU_SYSIDLE_NOT 0 /* Some CPU is not idle. */
+#define RCU_SYSIDLE_SHORT 1 /* All CPUs idle for brief period. */
+#define RCU_SYSIDLE_LONG 2 /* All CPUs idle for long enough. */
+#define RCU_SYSIDLE_FULL 3 /* All CPUs idle, ready for sysidle. */
+#define RCU_SYSIDLE_FULL_NOTED 4 /* Actually entered sysidle state. */
+
+/*
+ * Invoked to note exit from irq or task transition to idle. Note that
+ * usermode execution does -not- count as idle here! After all, we want
+ * to detect full-system idle states, not RCU quiescent states and grace
+ * periods. The caller must have disabled interrupts.
+ */
+static void rcu_sysidle_enter(struct rcu_dynticks *rdtp, int irq)
+{
+ unsigned long j;
+
+ /* Adjust nesting, check for fully idle. */
+ if (irq) {
+ rdtp->dynticks_idle_nesting--;
+ WARN_ON_ONCE(rdtp->dynticks_idle_nesting < 0);
+ if (rdtp->dynticks_idle_nesting != 0)
+ return; /* Still not fully idle. */
+ } else {
+ if ((rdtp->dynticks_idle_nesting & DYNTICK_TASK_NEST_MASK) ==
+ DYNTICK_TASK_NEST_VALUE) {
+ rdtp->dynticks_idle_nesting = 0;
+ } else {
+ rdtp->dynticks_idle_nesting -= DYNTICK_TASK_NEST_VALUE;
+ WARN_ON_ONCE(rdtp->dynticks_idle_nesting < 0);
+ return; /* Still not fully idle. */
+ }
+ }
+
+ /* Record start of fully idle period. */
+ j = jiffies;
+ ACCESS_ONCE(rdtp->dynticks_idle_jiffies) = j;
+ smp_mb__before_atomic_inc();
+ atomic_inc(&rdtp->dynticks_idle);
+ smp_mb__after_atomic_inc();
+ WARN_ON_ONCE(atomic_read(&rdtp->dynticks_idle) & 0x1);
+}
+
+/*
+ * Unconditionally force exit from full system-idle state. This is
+ * invoked when a normal CPU exits idle, but must be called separately
+ * for the timekeeping CPU (tick_do_timer_cpu). The reason for this
+ * is that the timekeeping CPU is permitted to take scheduling-clock
+ * interrupts while the system is in system-idle state, and of course
+ * rcu_sysidle_exit() has no way of distinguishing a scheduling-clock
+ * interrupt from any other type of interrupt.
+ */
+void rcu_sysidle_force_exit(void)
+{
+ int oldstate = ACCESS_ONCE(full_sysidle_state);
+ int newoldstate;
+
+ /*
+ * Each pass through the following loop attempts to exit full
+ * system-idle state. If contention proves to be a problem,
+ * a trylock-based contention tree could be used here.
+ */
+ while (oldstate > RCU_SYSIDLE_SHORT) {
+ newoldstate = cmpxchg(&full_sysidle_state,
+ oldstate, RCU_SYSIDLE_NOT);
+ if (oldstate == newoldstate &&
+ oldstate == RCU_SYSIDLE_FULL_NOTED) {
+ rcu_kick_nohz_cpu(tick_do_timer_cpu);
+ return; /* We cleared it, done! */
+ }
+ oldstate = newoldstate;
+ }
+ smp_mb(); /* Order initial oldstate fetch vs. later non-idle work. */
+}
+
+/*
+ * Invoked to note entry to irq or task transition from idle. Note that
+ * usermode execution does -not- count as idle here! The caller must
+ * have disabled interrupts.
+ */
+static void rcu_sysidle_exit(struct rcu_dynticks *rdtp, int irq)
+{
+ /* Adjust nesting, check for already non-idle. */
+ if (irq) {
+ rdtp->dynticks_idle_nesting++;
+ WARN_ON_ONCE(rdtp->dynticks_idle_nesting <= 0);
+ if (rdtp->dynticks_idle_nesting != 1)
+ return; /* Already non-idle. */
+ } else {
+ /*
+ * Allow for irq misnesting. Yes, it really is possible
+ * to enter an irq handler then never leave it, and maybe
+ * also vice versa. Handle both possibilities.
+ */
+ if (rdtp->dynticks_idle_nesting & DYNTICK_TASK_NEST_MASK) {
+ rdtp->dynticks_idle_nesting += DYNTICK_TASK_NEST_VALUE;
+ WARN_ON_ONCE(rdtp->dynticks_idle_nesting <= 0);
+ return; /* Already non-idle. */
+ } else {
+ rdtp->dynticks_idle_nesting = DYNTICK_TASK_EXIT_IDLE;
+ }
+ }
+
+ /* Record end of idle period. */
+ smp_mb__before_atomic_inc();
+ atomic_inc(&rdtp->dynticks_idle);
+ smp_mb__after_atomic_inc();
+ WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks_idle) & 0x1));
+
+ /*
+ * If we are the timekeeping CPU, we are permitted to be non-idle
+ * during a system-idle state. This must be the case, because
+ * the timekeeping CPU has to take scheduling-clock interrupts
+ * during the time that the system is transitioning to full
+ * system-idle state. This means that the timekeeping CPU must
+ * invoke rcu_sysidle_force_exit() directly if it does anything
+ * more than take a scheduling-clock interrupt.
+ */
+ if (smp_processor_id() == tick_do_timer_cpu)
+ return;
+
+ /* Update system-idle state: We are clearly no longer fully idle! */
+ rcu_sysidle_force_exit();
+}
+
+/*
+ * Check to see if the current CPU is idle. Note that usermode execution
+ * does not count as idle. The caller must have disabled interrupts.
+ */
+static void rcu_sysidle_check_cpu(struct rcu_data *rdp, bool *isidle,
+ unsigned long *maxj)
+{
+ int cur;
+ unsigned long j;
+ struct rcu_dynticks *rdtp = rdp->dynticks;
+
+ /*
+ * If some other CPU has already reported non-idle, if this is
+ * not the flavor of RCU that tracks sysidle state, or if this
+ * is an offline or the timekeeping CPU, nothing to do.
+ */
+ if (!*isidle || rdp->rsp != rcu_sysidle_state ||
+ cpu_is_offline(rdp->cpu) || rdp->cpu == tick_do_timer_cpu)
+ return;
+ if (rcu_gp_in_progress(rdp->rsp))
+ WARN_ON_ONCE(smp_processor_id() != tick_do_timer_cpu);
+
+ /* Pick up current idle and NMI-nesting counter and check. */
+ cur = atomic_read(&rdtp->dynticks_idle);
+ if (cur & 0x1) {
+ *isidle = false; /* We are not idle! */
+ return;
+ }
+ smp_mb(); /* Read counters before timestamps. */
+
+ /* Pick up timestamps. */
+ j = ACCESS_ONCE(rdtp->dynticks_idle_jiffies);
+ /* If this CPU entered idle more recently, update maxj timestamp. */
+ if (ULONG_CMP_LT(*maxj, j))
+ *maxj = j;
+}
+
+/*
+ * Is this the flavor of RCU that is handling full-system idle?
+ */
+static bool is_sysidle_rcu_state(struct rcu_state *rsp)
+{
+ return rsp == rcu_sysidle_state;
+}
+
+/*
+ * Bind the grace-period kthread for the sysidle flavor of RCU to the
+ * timekeeping CPU.
+ */
+static void rcu_bind_gp_kthread(void)
+{
+ int cpu = ACCESS_ONCE(tick_do_timer_cpu);
+
+ if (cpu < 0 || cpu >= nr_cpu_ids)
+ return;
+ if (raw_smp_processor_id() != cpu)
+ set_cpus_allowed_ptr(current, cpumask_of(cpu));
+}
+
+/*
+ * Return a delay in jiffies based on the number of CPUs, rcu_node
+ * leaf fanout, and jiffies tick rate. The idea is to allow larger
+ * systems more time to transition to full-idle state in order to
+ * avoid the cache thrashing that otherwise occur on the state variable.
+ * Really small systems (less than a couple of tens of CPUs) should
+ * instead use a single global atomically incremented counter, and later
+ * versions of this will automatically reconfigure themselves accordingly.
+ */
+static unsigned long rcu_sysidle_delay(void)
+{
+ if (nr_cpu_ids <= CONFIG_NO_HZ_FULL_SYSIDLE_SMALL)
+ return 0;
+ return DIV_ROUND_UP(nr_cpu_ids * HZ, rcu_fanout_leaf * 1000);
+}
+
+/*
+ * Advance the full-system-idle state. This is invoked when all of
+ * the non-timekeeping CPUs are idle.
+ */
+static void rcu_sysidle(unsigned long j)
+{
+ /* Check the current state. */
+ switch (ACCESS_ONCE(full_sysidle_state)) {
+ case RCU_SYSIDLE_NOT:
+
+ /* First time all are idle, so note a short idle period. */
+ ACCESS_ONCE(full_sysidle_state) = RCU_SYSIDLE_SHORT;
+ break;
+
+ case RCU_SYSIDLE_SHORT:
+
+ /*
+ * Idle for a bit, time to advance to next state?
+ * cmpxchg failure means race with non-idle, let them win.
+ */
+ if (ULONG_CMP_GE(jiffies, j + rcu_sysidle_delay()))
+ (void)cmpxchg(&full_sysidle_state,
+ RCU_SYSIDLE_SHORT, RCU_SYSIDLE_LONG);
+ break;
+
+ case RCU_SYSIDLE_LONG:
+
+ /*
+ * Do an additional check pass before advancing to full.
+ * cmpxchg failure means race with non-idle, let them win.
+ */
+ if (ULONG_CMP_GE(jiffies, j + rcu_sysidle_delay()))
+ (void)cmpxchg(&full_sysidle_state,
+ RCU_SYSIDLE_LONG, RCU_SYSIDLE_FULL);
+ break;
+
+ default:
+ break;
+ }
+}
+
+/*
+ * Found a non-idle non-timekeeping CPU, so kick the system-idle state
+ * back to the beginning.
+ */
+static void rcu_sysidle_cancel(void)
+{
+ smp_mb();
+ ACCESS_ONCE(full_sysidle_state) = RCU_SYSIDLE_NOT;
+}
+
+/*
+ * Update the sysidle state based on the results of a force-quiescent-state
+ * scan of the CPUs' dyntick-idle state.
+ */
+static void rcu_sysidle_report(struct rcu_state *rsp, int isidle,
+ unsigned long maxj, bool gpkt)
+{
+ if (rsp != rcu_sysidle_state)
+ return; /* Wrong flavor, ignore. */
+ if (gpkt && nr_cpu_ids <= CONFIG_NO_HZ_FULL_SYSIDLE_SMALL)
+ return; /* Running state machine from timekeeping CPU. */
+ if (isidle)
+ rcu_sysidle(maxj); /* More idle! */
+ else
+ rcu_sysidle_cancel(); /* Idle is over. */
+}
+
+/*
+ * Wrapper for rcu_sysidle_report() when called from the grace-period
+ * kthread's context.
+ */
+static void rcu_sysidle_report_gp(struct rcu_state *rsp, int isidle,
+ unsigned long maxj)
+{
+ rcu_sysidle_report(rsp, isidle, maxj, true);
+}
+
+/* Callback and function for forcing an RCU grace period. */
+struct rcu_sysidle_head {
+ struct rcu_head rh;
+ int inuse;
+};
+
+static void rcu_sysidle_cb(struct rcu_head *rhp)
+{
+ struct rcu_sysidle_head *rshp;
+
+ /*
+ * The following memory barrier is needed to replace the
+ * memory barriers that would normally be in the memory
+ * allocator.
+ */
+ smp_mb(); /* grace period precedes setting inuse. */
+
+ rshp = container_of(rhp, struct rcu_sysidle_head, rh);
+ ACCESS_ONCE(rshp->inuse) = 0;
+}
+
+/*
+ * Check to see if the system is fully idle, other than the timekeeping CPU.
+ * The caller must have disabled interrupts.
+ */
+bool rcu_sys_is_idle(void)
+{
+ static struct rcu_sysidle_head rsh;
+ int rss = ACCESS_ONCE(full_sysidle_state);
+
+ if (WARN_ON_ONCE(smp_processor_id() != tick_do_timer_cpu))
+ return false;
+
+ /* Handle small-system case by doing a full scan of CPUs. */
+ if (nr_cpu_ids <= CONFIG_NO_HZ_FULL_SYSIDLE_SMALL) {
+ int oldrss = rss - 1;
+
+ /*
+ * One pass to advance to each state up to _FULL.
+ * Give up if any pass fails to advance the state.
+ */
+ while (rss < RCU_SYSIDLE_FULL && oldrss < rss) {
+ int cpu;
+ bool isidle = true;
+ unsigned long maxj = jiffies - ULONG_MAX / 4;
+ struct rcu_data *rdp;
+
+ /* Scan all the CPUs looking for nonidle CPUs. */
+ for_each_possible_cpu(cpu) {
+ rdp = per_cpu_ptr(rcu_sysidle_state->rda, cpu);
+ rcu_sysidle_check_cpu(rdp, &isidle, &maxj);
+ if (!isidle)
+ break;
+ }
+ rcu_sysidle_report(rcu_sysidle_state,
+ isidle, maxj, false);
+ oldrss = rss;
+ rss = ACCESS_ONCE(full_sysidle_state);
+ }
+ }
+
+ /* If this is the first observation of an idle period, record it. */
+ if (rss == RCU_SYSIDLE_FULL) {
+ rss = cmpxchg(&full_sysidle_state,
+ RCU_SYSIDLE_FULL, RCU_SYSIDLE_FULL_NOTED);
+ return rss == RCU_SYSIDLE_FULL;
+ }
+
+ smp_mb(); /* ensure rss load happens before later caller actions. */
+
+ /* If already fully idle, tell the caller (in case of races). */
+ if (rss == RCU_SYSIDLE_FULL_NOTED)
+ return true;
+
+ /*
+ * If we aren't there yet, and a grace period is not in flight,
+ * initiate a grace period. Either way, tell the caller that
+ * we are not there yet. We use an xchg() rather than an assignment
+ * to make up for the memory barriers that would otherwise be
+ * provided by the memory allocator.
+ */
+ if (nr_cpu_ids > CONFIG_NO_HZ_FULL_SYSIDLE_SMALL &&
+ !rcu_gp_in_progress(rcu_sysidle_state) &&
+ !rsh.inuse && xchg(&rsh.inuse, 1) == 0)
+ call_rcu(&rsh.rh, rcu_sysidle_cb);
+ return false;
+}
+
+/*
+ * Initialize dynticks sysidle state for CPUs coming online.
+ */
+static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp)
+{
+ rdtp->dynticks_idle_nesting = DYNTICK_TASK_NEST_VALUE;
+}
+
+#else /* #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
+
+static void rcu_sysidle_enter(struct rcu_dynticks *rdtp, int irq)
+{
+}
+
+static void rcu_sysidle_exit(struct rcu_dynticks *rdtp, int irq)
+{
+}
+
+static void rcu_sysidle_check_cpu(struct rcu_data *rdp, bool *isidle,
+ unsigned long *maxj)
+{
+}
+
+static bool is_sysidle_rcu_state(struct rcu_state *rsp)
+{
+ return false;
+}
+
+static void rcu_bind_gp_kthread(void)
+{
+}
+
+static void rcu_sysidle_report_gp(struct rcu_state *rsp, int isidle,
+ unsigned long maxj)
+{
+}
+
+static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp)
+{
+}
+
+#endif /* #else #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6f006002b211..57c186d9477e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6820,7 +6820,7 @@ void sched_move_task(struct task_struct *tsk)
if (unlikely(running))
tsk->sched_class->put_prev_task(rq, tsk);
- tg = container_of(task_subsys_state_check(tsk, cpu_cgroup_subsys_id,
+ tg = container_of(task_css_check(tsk, cpu_cgroup_subsys_id,
lockdep_is_held(&tsk->sighand->siglock)),
struct task_group, css);
tg = autogroup_task_group(tsk, tg);
@@ -7142,23 +7142,22 @@ int sched_rt_handler(struct ctl_table *table, int write,
#ifdef CONFIG_CGROUP_SCHED
-/* return corresponding task_group object of a cgroup */
-static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
+static inline struct task_group *css_tg(struct cgroup_subsys_state *css)
{
- return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
- struct task_group, css);
+ return css ? container_of(css, struct task_group, css) : NULL;
}
-static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
+static struct cgroup_subsys_state *
+cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
{
- struct task_group *tg, *parent;
+ struct task_group *parent = css_tg(parent_css);
+ struct task_group *tg;
- if (!cgrp->parent) {
+ if (!parent) {
/* This is early initialization for the top cgroup */
return &root_task_group.css;
}
- parent = cgroup_tg(cgrp->parent);
tg = sched_create_group(parent);
if (IS_ERR(tg))
return ERR_PTR(-ENOMEM);
@@ -7166,41 +7165,38 @@ static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
return &tg->css;
}
-static int cpu_cgroup_css_online(struct cgroup *cgrp)
+static int cpu_cgroup_css_online(struct cgroup_subsys_state *css)
{
- struct task_group *tg = cgroup_tg(cgrp);
- struct task_group *parent;
-
- if (!cgrp->parent)
- return 0;
+ struct task_group *tg = css_tg(css);
+ struct task_group *parent = css_tg(css_parent(css));
- parent = cgroup_tg(cgrp->parent);
- sched_online_group(tg, parent);
+ if (parent)
+ sched_online_group(tg, parent);
return 0;
}
-static void cpu_cgroup_css_free(struct cgroup *cgrp)
+static void cpu_cgroup_css_free(struct cgroup_subsys_state *css)
{
- struct task_group *tg = cgroup_tg(cgrp);
+ struct task_group *tg = css_tg(css);
sched_destroy_group(tg);
}
-static void cpu_cgroup_css_offline(struct cgroup *cgrp)
+static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css)
{
- struct task_group *tg = cgroup_tg(cgrp);
+ struct task_group *tg = css_tg(css);
sched_offline_group(tg);
}
-static int cpu_cgroup_can_attach(struct cgroup *cgrp,
+static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
struct cgroup_taskset *tset)
{
struct task_struct *task;
- cgroup_taskset_for_each(task, cgrp, tset) {
+ cgroup_taskset_for_each(task, css, tset) {
#ifdef CONFIG_RT_GROUP_SCHED
- if (!sched_rt_can_attach(cgroup_tg(cgrp), task))
+ if (!sched_rt_can_attach(css_tg(css), task))
return -EINVAL;
#else
/* We don't support RT-tasks being in separate groups */
@@ -7211,18 +7207,18 @@ static int cpu_cgroup_can_attach(struct cgroup *cgrp,
return 0;
}
-static void cpu_cgroup_attach(struct cgroup *cgrp,
+static void cpu_cgroup_attach(struct cgroup_subsys_state *css,
struct cgroup_taskset *tset)
{
struct task_struct *task;
- cgroup_taskset_for_each(task, cgrp, tset)
+ cgroup_taskset_for_each(task, css, tset)
sched_move_task(task);
}
-static void
-cpu_cgroup_exit(struct cgroup *cgrp, struct cgroup *old_cgrp,
- struct task_struct *task)
+static void cpu_cgroup_exit(struct cgroup_subsys_state *css,
+ struct cgroup_subsys_state *old_css,
+ struct task_struct *task)
{
/*
* cgroup_exit() is called in the copy_process() failure path.
@@ -7236,15 +7232,16 @@ cpu_cgroup_exit(struct cgroup *cgrp, struct cgroup *old_cgrp,
}
#ifdef CONFIG_FAIR_GROUP_SCHED
-static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype,
- u64 shareval)
+static int cpu_shares_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 shareval)
{
- return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval));
+ return sched_group_set_shares(css_tg(css), scale_load(shareval));
}
-static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
+static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- struct task_group *tg = cgroup_tg(cgrp);
+ struct task_group *tg = css_tg(css);
return (u64) scale_load_down(tg->shares);
}
@@ -7366,26 +7363,28 @@ long tg_get_cfs_period(struct task_group *tg)
return cfs_period_us;
}
-static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft)
+static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return tg_get_cfs_quota(cgroup_tg(cgrp));
+ return tg_get_cfs_quota(css_tg(css));
}
-static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype,
- s64 cfs_quota_us)
+static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, s64 cfs_quota_us)
{
- return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us);
+ return tg_set_cfs_quota(css_tg(css), cfs_quota_us);
}
-static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft)
+static u64 cpu_cfs_period_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return tg_get_cfs_period(cgroup_tg(cgrp));
+ return tg_get_cfs_period(css_tg(css));
}
-static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype,
- u64 cfs_period_us)
+static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 cfs_period_us)
{
- return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us);
+ return tg_set_cfs_period(css_tg(css), cfs_period_us);
}
struct cfs_schedulable_data {
@@ -7466,10 +7465,10 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
return ret;
}
-static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft,
+static int cpu_stats_show(struct cgroup_subsys_state *css, struct cftype *cft,
struct cgroup_map_cb *cb)
{
- struct task_group *tg = cgroup_tg(cgrp);
+ struct task_group *tg = css_tg(css);
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
cb->fill(cb, "nr_periods", cfs_b->nr_periods);
@@ -7482,26 +7481,28 @@ static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft,
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
-static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
- s64 val)
+static int cpu_rt_runtime_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, s64 val)
{
- return sched_group_set_rt_runtime(cgroup_tg(cgrp), val);
+ return sched_group_set_rt_runtime(css_tg(css), val);
}
-static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft)
+static s64 cpu_rt_runtime_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return sched_group_rt_runtime(cgroup_tg(cgrp));
+ return sched_group_rt_runtime(css_tg(css));
}
-static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype,
- u64 rt_period_us)
+static int cpu_rt_period_write_uint(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 rt_period_us)
{
- return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us);
+ return sched_group_set_rt_period(css_tg(css), rt_period_us);
}
-static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft)
+static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- return sched_group_rt_period(cgroup_tg(cgrp));
+ return sched_group_rt_period(css_tg(css));
}
#endif /* CONFIG_RT_GROUP_SCHED */
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index dbb7e2cd95eb..f64722ff0299 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -33,30 +33,20 @@ struct cpuacct {
struct kernel_cpustat __percpu *cpustat;
};
-/* return cpu accounting group corresponding to this container */
-static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
+static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
{
- return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
- struct cpuacct, css);
+ return css ? container_of(css, struct cpuacct, css) : NULL;
}
/* return cpu accounting group to which this task belongs */
static inline struct cpuacct *task_ca(struct task_struct *tsk)
{
- return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
- struct cpuacct, css);
-}
-
-static inline struct cpuacct *__parent_ca(struct cpuacct *ca)
-{
- return cgroup_ca(ca->css.cgroup->parent);
+ return css_ca(task_css(tsk, cpuacct_subsys_id));
}
static inline struct cpuacct *parent_ca(struct cpuacct *ca)
{
- if (!ca->css.cgroup->parent)
- return NULL;
- return cgroup_ca(ca->css.cgroup->parent);
+ return css_ca(css_parent(&ca->css));
}
static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);
@@ -66,11 +56,12 @@ static struct cpuacct root_cpuacct = {
};
/* create a new cpu accounting group */
-static struct cgroup_subsys_state *cpuacct_css_alloc(struct cgroup *cgrp)
+static struct cgroup_subsys_state *
+cpuacct_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct cpuacct *ca;
- if (!cgrp->parent)
+ if (!parent_css)
return &root_cpuacct.css;
ca = kzalloc(sizeof(*ca), GFP_KERNEL);
@@ -96,9 +87,9 @@ out:
}
/* destroy an existing cpu accounting group */
-static void cpuacct_css_free(struct cgroup *cgrp)
+static void cpuacct_css_free(struct cgroup_subsys_state *css)
{
- struct cpuacct *ca = cgroup_ca(cgrp);
+ struct cpuacct *ca = css_ca(css);
free_percpu(ca->cpustat);
free_percpu(ca->cpuusage);
@@ -141,9 +132,9 @@ static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
}
/* return total cpu usage (in nanoseconds) of a group */
-static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
+static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)
{
- struct cpuacct *ca = cgroup_ca(cgrp);
+ struct cpuacct *ca = css_ca(css);
u64 totalcpuusage = 0;
int i;
@@ -153,10 +144,10 @@ static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
return totalcpuusage;
}
-static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
- u64 reset)
+static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
+ u64 reset)
{
- struct cpuacct *ca = cgroup_ca(cgrp);
+ struct cpuacct *ca = css_ca(css);
int err = 0;
int i;
@@ -172,10 +163,10 @@ out:
return err;
}
-static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
- struct seq_file *m)
+static int cpuacct_percpu_seq_read(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct seq_file *m)
{
- struct cpuacct *ca = cgroup_ca(cgroup);
+ struct cpuacct *ca = css_ca(css);
u64 percpu;
int i;
@@ -192,10 +183,10 @@ static const char * const cpuacct_stat_desc[] = {
[CPUACCT_STAT_SYSTEM] = "system",
};
-static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
- struct cgroup_map_cb *cb)
+static int cpuacct_stats_show(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct cgroup_map_cb *cb)
{
- struct cpuacct *ca = cgroup_ca(cgrp);
+ struct cpuacct *ca = css_ca(css);
int cpu;
s64 val = 0;
@@ -281,7 +272,7 @@ void cpuacct_account_field(struct task_struct *p, int index, u64 val)
while (ca != &root_cpuacct) {
kcpustat = this_cpu_ptr(ca->cpustat);
kcpustat->cpustat[index] += val;
- ca = __parent_ca(ca);
+ ca = parent_ca(ca);
}
rcu_read_unlock();
}
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4c1cb8029feb..b3c5653e1dca 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -665,9 +665,9 @@ extern int group_balance_cpu(struct sched_group *sg);
/*
* Return the group to which this tasks belongs.
*
- * We cannot use task_subsys_state() and friends because the cgroup
- * subsystem changes that value before the cgroup_subsys::attach() method
- * is called, therefore we cannot pin it and might observe the wrong value.
+ * We cannot use task_css() and friends because the cgroup subsystem
+ * changes that value before the cgroup_subsys::attach() method is called,
+ * therefore we cannot pin it and might observe the wrong value.
*
* The same is true for autogroup's p->signal->autogroup->tg, the autogroup
* core changes this before calling sched_move_task().
diff --git a/kernel/smp.c b/kernel/smp.c
index fe9f773d7114..b1c9034bdfcb 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -278,8 +278,6 @@ EXPORT_SYMBOL(smp_call_function_single);
* @wait: If true, wait until function has completed.
*
* Returns 0 on success, else a negative status code (if no cpus were online).
- * Note that @wait will be implicitly turned on in case of allocation failures,
- * since we fall back to on-stack allocation.
*
* Selection preference:
* 1) current cpu if in @mask
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 70f27e89012b..3381f098070f 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -134,6 +134,56 @@ config NO_HZ_FULL_ALL
Note the boot CPU will still be kept outside the range to
handle the timekeeping duty.
+config NO_HZ_FULL_SYSIDLE
+ bool "Detect full-system idle state for full dynticks system"
+ depends on NO_HZ_FULL
+ default n
+ help
+ At least one CPU must keep the scheduling-clock tick running for
+ timekeeping purposes whenever there is a non-idle CPU, where
+ "non-idle" also includes dynticks CPUs as long as they are
+ running non-idle tasks. Because the underlying adaptive-tick
+ support cannot distinguish between all CPUs being idle and
+ all CPUs each running a single task in dynticks mode, the
+ underlying support simply ensures that there is always a CPU
+ handling the scheduling-clock tick, whether or not all CPUs
+ are idle. This Kconfig option enables scalable detection of
+ the all-CPUs-idle state, thus allowing the scheduling-clock
+ tick to be disabled when all CPUs are idle. Note that scalable
+ detection of the all-CPUs-idle state means that larger systems
+ will be slower to declare the all-CPUs-idle state.
+
+ Say Y if you would like to help debug all-CPUs-idle detection.
+
+ Say N if you are unsure.
+
+config NO_HZ_FULL_SYSIDLE_SMALL
+ int "Number of CPUs above which large-system approach is used"
+ depends on NO_HZ_FULL_SYSIDLE
+ range 1 NR_CPUS
+ default 8
+ help
+ The full-system idle detection mechanism takes a lazy approach
+ on large systems, as is required to attain decent scalability.
+ However, on smaller systems, scalability is not anywhere near as
+ large a concern as is energy efficiency. The sysidle subsystem
+ therefore uses a fast but non-scalable algorithm for small
+ systems and a lazier but scalable algorithm for large systems.
+ This Kconfig parameter defines the number of CPUs in the largest
+ system that will be considered to be "small".
+
+ The default value will be fine in most cases. Battery-powered
+ systems that (1) enable NO_HZ_FULL_SYSIDLE, (2) have larger
+ numbers of CPUs, and (3) are suffering from battery-lifetime
+ problems due to long sysidle latencies might wish to experiment
+ with larger values for this Kconfig parameter. On the other
+ hand, they might be even better served by disabling NO_HZ_FULL
+ entirely, given that NO_HZ_FULL is intended for HPC and
+ real-time workloads that at present do not tend to be run on
+ battery-powered systems.
+
+ Take the default if you are unsure.
+
config NO_HZ
bool "Old Idle dynticks config"
depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index afaae41b0a02..fe39acd4c1aa 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1022,6 +1022,9 @@ extern struct list_head ftrace_events;
extern const char *__start___trace_bprintk_fmt[];
extern const char *__stop___trace_bprintk_fmt[];
+extern const char *__start___tracepoint_str[];
+extern const char *__stop___tracepoint_str[];
+
void trace_printk_init_buffers(void);
void trace_printk_start_comm(void);
int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index a9077c1b4ad3..2900817ba65c 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -244,12 +244,31 @@ static const char **find_next(void *v, loff_t *pos)
{
const char **fmt = v;
int start_index;
+ int last_index;
start_index = __stop___trace_bprintk_fmt - __start___trace_bprintk_fmt;
if (*pos < start_index)
return __start___trace_bprintk_fmt + *pos;
+ /*
+ * The __tracepoint_str section is treated the same as the
+ * __trace_printk_fmt section. The difference is that the
+ * __trace_printk_fmt section should only be used by trace_printk()
+ * in a debugging environment, as if anything exists in that section
+ * the trace_prink() helper buffers are allocated, which would just
+ * waste space in a production environment.
+ *
+ * The __tracepoint_str sections on the other hand are used by
+ * tracepoints which need to map pointers to their strings to
+ * the ASCII text for userspace.
+ */
+ last_index = start_index;
+ start_index = __stop___tracepoint_str - __start___tracepoint_str;
+
+ if (*pos < last_index + start_index)
+ return __start___tracepoint_str + (*pos - last_index);
+
return find_next_mod_format(start_index, v, fmt, pos);
}
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 7f5d4be22034..29b79852a845 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -16,9 +16,10 @@
*
* This is the generic async execution mechanism. Work items as are
* executed in process context. The worker pool is shared and
- * automatically managed. There is one worker pool for each CPU and
- * one extra for works which are better served by workers which are
- * not bound to any specific CPU.
+ * automatically managed. There are two worker pools for each CPU (one for
+ * normal work items and the other for high priority ones) and some extra
+ * pools for workqueues which are not bound to any specific CPU - the
+ * number of these backing pools is dynamic.
*
* Please read Documentation/workqueue.txt for details.
*/
@@ -2033,8 +2034,11 @@ static bool maybe_destroy_workers(struct worker_pool *pool)
* multiple times. Does GFP_KERNEL allocations.
*
* RETURNS:
- * spin_lock_irq(pool->lock) which may be released and regrabbed
- * multiple times. Does GFP_KERNEL allocations.
+ * %false if the pool don't need management and the caller can safely start
+ * processing works, %true indicates that the function released pool->lock
+ * and reacquired it to perform some management function and that the
+ * conditions that the caller verified while holding the lock before
+ * calling the function might no longer be true.
*/
static bool manage_workers(struct worker *worker)
{
@@ -2201,6 +2205,15 @@ __acquires(&pool->lock)
dump_stack();
}
+ /*
+ * The following prevents a kworker from hogging CPU on !PREEMPT
+ * kernels, where a requeueing work item waiting for something to
+ * happen could deadlock with stop_machine as such work item could
+ * indefinitely requeue itself while all other CPUs are trapped in
+ * stop_machine.
+ */
+ cond_resched();
+
spin_lock_irq(&pool->lock);
/* clear cpu intensive status */
@@ -3086,25 +3099,26 @@ static struct workqueue_struct *dev_to_wq(struct device *dev)
return wq_dev->wq;
}
-static ssize_t wq_per_cpu_show(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t per_cpu_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
struct workqueue_struct *wq = dev_to_wq(dev);
return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)!(wq->flags & WQ_UNBOUND));
}
+static DEVICE_ATTR_RO(per_cpu);
-static ssize_t wq_max_active_show(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t max_active_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
struct workqueue_struct *wq = dev_to_wq(dev);
return scnprintf(buf, PAGE_SIZE, "%d\n", wq->saved_max_active);
}
-static ssize_t wq_max_active_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t max_active_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
{
struct workqueue_struct *wq = dev_to_wq(dev);
int val;
@@ -3115,12 +3129,14 @@ static ssize_t wq_max_active_store(struct device *dev,
workqueue_set_max_active(wq, val);
return count;
}
+static DEVICE_ATTR_RW(max_active);
-static struct device_attribute wq_sysfs_attrs[] = {
- __ATTR(per_cpu, 0444, wq_per_cpu_show, NULL),
- __ATTR(max_active, 0644, wq_max_active_show, wq_max_active_store),
- __ATTR_NULL,
+static struct attribute *wq_sysfs_attrs[] = {
+ &dev_attr_per_cpu.attr,
+ &dev_attr_max_active.attr,
+ NULL,
};
+ATTRIBUTE_GROUPS(wq_sysfs);
static ssize_t wq_pool_ids_show(struct device *dev,
struct device_attribute *attr, char *buf)
@@ -3270,7 +3286,7 @@ static struct device_attribute wq_sysfs_unbound_attrs[] = {
static struct bus_type wq_subsys = {
.name = "workqueue",
- .dev_attrs = wq_sysfs_attrs,
+ .dev_groups = wq_sysfs_groups,
};
static int __init wq_sysfs_init(void)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.