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-rw-r--r--kernel/acct.c23
-rw-r--r--kernel/audit.c17
-rw-r--r--kernel/cgroup.c4
-rw-r--r--kernel/fork.c2
-rw-r--r--kernel/futex.c6
-rw-r--r--kernel/futex_compat.c2
-rw-r--r--kernel/marker.c31
-rw-r--r--kernel/power/Kconfig2
-rw-r--r--kernel/power/snapshot.c41
-rw-r--r--kernel/printk.c83
-rw-r--r--kernel/relay.c12
-rw-r--r--kernel/sched.c115
-rw-r--r--kernel/sched_debug.c1
-rw-r--r--kernel/sched_fair.c291
-rw-r--r--kernel/time/clocksource.c16
-rw-r--r--kernel/time/timekeeping.c4
-rw-r--r--kernel/timer.c10
17 files changed, 420 insertions, 240 deletions
diff --git a/kernel/acct.c b/kernel/acct.c
index 521dfa53cb99..91e1cfd734d2 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -58,6 +58,7 @@
#include <asm/uaccess.h>
#include <asm/div64.h>
#include <linux/blkdev.h> /* sector_div */
+#include <linux/pid_namespace.h>
/*
* These constants control the amount of freespace that suspend and
@@ -74,7 +75,7 @@ int acct_parm[3] = {4, 2, 30};
/*
* External references and all of the globals.
*/
-static void do_acct_process(struct file *);
+static void do_acct_process(struct pid_namespace *ns, struct file *);
/*
* This structure is used so that all the data protected by lock
@@ -86,6 +87,7 @@ struct acct_glbs {
volatile int active;
volatile int needcheck;
struct file *file;
+ struct pid_namespace *ns;
struct timer_list timer;
};
@@ -175,9 +177,11 @@ out:
static void acct_file_reopen(struct file *file)
{
struct file *old_acct = NULL;
+ struct pid_namespace *old_ns = NULL;
if (acct_globals.file) {
old_acct = acct_globals.file;
+ old_ns = acct_globals.ns;
del_timer(&acct_globals.timer);
acct_globals.active = 0;
acct_globals.needcheck = 0;
@@ -185,6 +189,7 @@ static void acct_file_reopen(struct file *file)
}
if (file) {
acct_globals.file = file;
+ acct_globals.ns = get_pid_ns(task_active_pid_ns(current));
acct_globals.needcheck = 0;
acct_globals.active = 1;
/* It's been deleted if it was used before so this is safe */
@@ -196,8 +201,9 @@ static void acct_file_reopen(struct file *file)
if (old_acct) {
mnt_unpin(old_acct->f_path.mnt);
spin_unlock(&acct_globals.lock);
- do_acct_process(old_acct);
+ do_acct_process(old_ns, old_acct);
filp_close(old_acct, NULL);
+ put_pid_ns(old_ns);
spin_lock(&acct_globals.lock);
}
}
@@ -419,7 +425,7 @@ static u32 encode_float(u64 value)
/*
* do_acct_process does all actual work. Caller holds the reference to file.
*/
-static void do_acct_process(struct file *file)
+static void do_acct_process(struct pid_namespace *ns, struct file *file)
{
struct pacct_struct *pacct = &current->signal->pacct;
acct_t ac;
@@ -481,8 +487,10 @@ static void do_acct_process(struct file *file)
ac.ac_gid16 = current->gid;
#endif
#if ACCT_VERSION==3
- ac.ac_pid = current->tgid;
- ac.ac_ppid = current->real_parent->tgid;
+ ac.ac_pid = task_tgid_nr_ns(current, ns);
+ rcu_read_lock();
+ ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns);
+ rcu_read_unlock();
#endif
spin_lock_irq(&current->sighand->siglock);
@@ -578,6 +586,7 @@ void acct_collect(long exitcode, int group_dead)
void acct_process(void)
{
struct file *file = NULL;
+ struct pid_namespace *ns;
/*
* accelerate the common fastpath:
@@ -592,8 +601,10 @@ void acct_process(void)
return;
}
get_file(file);
+ ns = get_pid_ns(acct_globals.ns);
spin_unlock(&acct_globals.lock);
- do_acct_process(file);
+ do_acct_process(ns, file);
fput(file);
+ put_pid_ns(ns);
}
diff --git a/kernel/audit.c b/kernel/audit.c
index 10c4930c2bbf..b782b046543d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -78,9 +78,13 @@ static int audit_default;
/* If auditing cannot proceed, audit_failure selects what happens. */
static int audit_failure = AUDIT_FAIL_PRINTK;
-/* If audit records are to be written to the netlink socket, audit_pid
- * contains the (non-zero) pid. */
+/*
+ * If audit records are to be written to the netlink socket, audit_pid
+ * contains the pid of the auditd process and audit_nlk_pid contains
+ * the pid to use to send netlink messages to that process.
+ */
int audit_pid;
+static int audit_nlk_pid;
/* If audit_rate_limit is non-zero, limit the rate of sending audit records
* to that number per second. This prevents DoS attacks, but results in
@@ -350,7 +354,7 @@ static int kauditd_thread(void *dummy)
wake_up(&audit_backlog_wait);
if (skb) {
if (audit_pid) {
- int err = netlink_unicast(audit_sock, skb, audit_pid, 0);
+ int err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
if (err < 0) {
BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */
printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
@@ -626,6 +630,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
sid, 1);
audit_pid = new_pid;
+ audit_nlk_pid = NETLINK_CB(skb).pid;
}
if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
err = audit_set_rate_limit(status_get->rate_limit,
@@ -1264,8 +1269,8 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
/**
* audit_string_contains_control - does a string need to be logged in hex
- * @string - string to be checked
- * @len - max length of the string to check
+ * @string: string to be checked
+ * @len: max length of the string to check
*/
int audit_string_contains_control(const char *string, size_t len)
{
@@ -1280,7 +1285,7 @@ int audit_string_contains_control(const char *string, size_t len)
/**
* audit_log_n_untrustedstring - log a string that may contain random characters
* @ab: audit_buffer
- * @len: lenth of string (not including trailing null)
+ * @len: length of string (not including trailing null)
* @string: string to be logged
*
* This code will escape a string that is passed to it if the string
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e9c2fb01e89b..53d86b4b0ce0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2082,7 +2082,7 @@ static int cgroup_tasks_open(struct inode *unused, struct file *file)
kfree(pidarray);
} else {
- ctr->buf = 0;
+ ctr->buf = NULL;
ctr->bufsz = 0;
}
file->private_data = ctr;
@@ -2614,7 +2614,7 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
static int cgroupstats_open(struct inode *inode, struct file *file)
{
- return single_open(file, proc_cgroupstats_show, 0);
+ return single_open(file, proc_cgroupstats_show, NULL);
}
static struct file_operations proc_cgroupstats_operations = {
diff --git a/kernel/fork.c b/kernel/fork.c
index dd249c37b3a3..9c042f901570 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -394,7 +394,6 @@ void __mmdrop(struct mm_struct *mm)
{
BUG_ON(mm == &init_mm);
mm_free_pgd(mm);
- mm_free_cgroup(mm);
destroy_context(mm);
free_mm(mm);
}
@@ -416,6 +415,7 @@ void mmput(struct mm_struct *mm)
spin_unlock(&mmlist_lock);
}
put_swap_token(mm);
+ mm_free_cgroup(mm);
mmdrop(mm);
}
}
diff --git a/kernel/futex.c b/kernel/futex.c
index 06968cd79200..e43945e995f5 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -281,7 +281,7 @@ static int get_futex_key(u32 __user *uaddr, struct rw_semaphore *fshared,
*/
static void get_futex_key_refs(union futex_key *key)
{
- if (key->both.ptr == 0)
+ if (key->both.ptr == NULL)
return;
switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
case FUT_OFF_INODE:
@@ -2158,7 +2158,7 @@ static struct file_system_type futex_fs_type = {
.kill_sb = kill_anon_super,
};
-static int __init init(void)
+static int __init futex_init(void)
{
u32 curval;
int i;
@@ -2194,4 +2194,4 @@ static int __init init(void)
return 0;
}
-__initcall(init);
+__initcall(futex_init);
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index ff90f049f8f6..04ac3a9e42cf 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -30,7 +30,7 @@ fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry,
return 0;
}
-static void __user *futex_uaddr(struct robust_list *entry,
+static void __user *futex_uaddr(struct robust_list __user *entry,
compat_long_t futex_offset)
{
compat_uptr_t base = ptr_to_compat(entry);
diff --git a/kernel/marker.c b/kernel/marker.c
index 48a4ea5afffd..041c33e3e95c 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -104,18 +104,18 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
char ptype;
/*
- * disabling preemption to make sure the teardown of the callbacks can
- * be done correctly when they are in modules and they insure RCU read
- * coherency.
+ * preempt_disable does two things : disabling preemption to make sure
+ * the teardown of the callbacks can be done correctly when they are in
+ * modules and they insure RCU read coherency.
*/
preempt_disable();
- ptype = ACCESS_ONCE(mdata->ptype);
+ ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
/* Must read the ptype before ptr. They are not data dependant,
* so we put an explicit smp_rmb() here. */
smp_rmb();
- func = ACCESS_ONCE(mdata->single.func);
+ func = mdata->single.func;
/* Must read the ptr before private data. They are not data
* dependant, so we put an explicit smp_rmb() here. */
smp_rmb();
@@ -133,7 +133,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
* in the fast path, so put the explicit barrier here.
*/
smp_read_barrier_depends();
- multi = ACCESS_ONCE(mdata->multi);
+ multi = mdata->multi;
for (i = 0; multi[i].func; i++) {
va_start(args, fmt);
multi[i].func(multi[i].probe_private, call_private, fmt,
@@ -161,13 +161,13 @@ void marker_probe_cb_noarg(const struct marker *mdata,
char ptype;
preempt_disable();
- ptype = ACCESS_ONCE(mdata->ptype);
+ ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
/* Must read the ptype before ptr. They are not data dependant,
* so we put an explicit smp_rmb() here. */
smp_rmb();
- func = ACCESS_ONCE(mdata->single.func);
+ func = mdata->single.func;
/* Must read the ptr before private data. They are not data
* dependant, so we put an explicit smp_rmb() here. */
smp_rmb();
@@ -183,7 +183,7 @@ void marker_probe_cb_noarg(const struct marker *mdata,
* in the fast path, so put the explicit barrier here.
*/
smp_read_barrier_depends();
- multi = ACCESS_ONCE(mdata->multi);
+ multi = mdata->multi;
for (i = 0; multi[i].func; i++)
multi[i].func(multi[i].probe_private, call_private, fmt,
&args);
@@ -551,9 +551,9 @@ static int set_marker(struct marker_entry **entry, struct marker *elem,
/*
* Disable a marker and its probe callback.
- * Note: only after a synchronize_sched() issued after setting elem->call to the
- * empty function insures that the original callback is not used anymore. This
- * insured by preemption disabling around the call site.
+ * Note: only waiting an RCU period after setting elem->call to the empty
+ * function insures that the original callback is not used anymore. This insured
+ * by preempt_disable around the call site.
*/
static void disable_marker(struct marker *elem)
{
@@ -565,8 +565,8 @@ static void disable_marker(struct marker *elem)
elem->ptype = 0; /* single probe */
/*
* Leave the private data and id there, because removal is racy and
- * should be done only after a synchronize_sched(). These are never used
- * until the next initialization anyway.
+ * should be done only after an RCU period. These are never used until
+ * the next initialization anyway.
*/
}
@@ -601,9 +601,6 @@ void marker_update_probe_range(struct marker *begin,
/*
* Update probes, removing the faulty probes.
- * Issues a synchronize_sched() when no reference to the module passed
- * as parameter is found in the probes so the probe module can be
- * safely unloaded from now on.
*
* Internal callback only changed before the first probe is connected to it.
* Single probe private data can only be changed on 0 -> 1 and 2 -> 1
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 79833170bb9c..6233f3b4ae66 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -190,7 +190,7 @@ config APM_EMULATION
notification of APM "events" (e.g. battery status change).
In order to use APM, you will need supporting software. For location
- and more information, read <file:Documentation/pm.txt> and the
+ and more information, read <file:Documentation/power/pm.txt> and the
Battery Powered Linux mini-HOWTO, available from
<http://www.tldp.org/docs.html#howto>.
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 72a020cabb4c..5f91a07c4eac 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -447,7 +447,7 @@ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
* of @bm->cur_zone_bm are updated.
*/
-static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
+static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
void **addr, unsigned int *bit_nr)
{
struct zone_bitmap *zone_bm;
@@ -461,7 +461,8 @@ static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
zone_bm = zone_bm->next;
- BUG_ON(!zone_bm);
+ if (!zone_bm)
+ return -EFAULT;
}
bm->cur.zone_bm = zone_bm;
}
@@ -479,23 +480,40 @@ static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
pfn -= bb->start_pfn;
*bit_nr = pfn % BM_BITS_PER_CHUNK;
*addr = bb->data + pfn / BM_BITS_PER_CHUNK;
+ return 0;
}
static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
{
void *addr;
unsigned int bit;
+ int error;
- memory_bm_find_bit(bm, pfn, &addr, &bit);
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ BUG_ON(error);
set_bit(bit, addr);
}
+static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
+{
+ void *addr;
+ unsigned int bit;
+ int error;
+
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ if (!error)
+ set_bit(bit, addr);
+ return error;
+}
+
static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
{
void *addr;
unsigned int bit;
+ int error;
- memory_bm_find_bit(bm, pfn, &addr, &bit);
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ BUG_ON(error);
clear_bit(bit, addr);
}
@@ -503,8 +521,10 @@ static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
{
void *addr;
unsigned int bit;
+ int error;
- memory_bm_find_bit(bm, pfn, &addr, &bit);
+ error = memory_bm_find_bit(bm, pfn, &addr, &bit);
+ BUG_ON(error);
return test_bit(bit, addr);
}
@@ -709,8 +729,15 @@ static void mark_nosave_pages(struct memory_bitmap *bm)
region->end_pfn << PAGE_SHIFT);
for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
- if (pfn_valid(pfn))
- memory_bm_set_bit(bm, pfn);
+ if (pfn_valid(pfn)) {
+ /*
+ * It is safe to ignore the result of
+ * mem_bm_set_bit_check() here, since we won't
+ * touch the PFNs for which the error is
+ * returned anyway.
+ */
+ mem_bm_set_bit_check(bm, pfn);
+ }
}
}
diff --git a/kernel/printk.c b/kernel/printk.c
index 9adc2a473e6e..c46a20a19a15 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -616,6 +616,40 @@ asmlinkage int printk(const char *fmt, ...)
/* cpu currently holding logbuf_lock */
static volatile unsigned int printk_cpu = UINT_MAX;
+/*
+ * Can we actually use the console at this time on this cpu?
+ *
+ * Console drivers may assume that per-cpu resources have
+ * been allocated. So unless they're explicitly marked as
+ * being able to cope (CON_ANYTIME) don't call them until
+ * this CPU is officially up.
+ */
+static inline int can_use_console(unsigned int cpu)
+{
+ return cpu_online(cpu) || have_callable_console();
+}
+
+/*
+ * Try to get console ownership to actually show the kernel
+ * messages from a 'printk'. Return true (and with the
+ * console_semaphore held, and 'console_locked' set) if it
+ * is successful, false otherwise.
+ *
+ * This gets called with the 'logbuf_lock' spinlock held and
+ * interrupts disabled. It should return with 'lockbuf_lock'
+ * released but interrupts still disabled.
+ */
+static int acquire_console_semaphore_for_printk(unsigned int cpu)
+{
+ int retval = 0;
+
+ if (can_use_console(cpu))
+ retval = !try_acquire_console_sem();
+ printk_cpu = UINT_MAX;
+ spin_unlock(&logbuf_lock);
+ return retval;
+}
+
const char printk_recursion_bug_msg [] =
KERN_CRIT "BUG: recent printk recursion!\n";
static int printk_recursion_bug;
@@ -725,43 +759,22 @@ asmlinkage int vprintk(const char *fmt, va_list args)
log_level_unknown = 1;
}
- if (!down_trylock(&console_sem)) {
- /*
- * We own the drivers. We can drop the spinlock and
- * let release_console_sem() print the text, maybe ...
- */
- console_locked = 1;
- printk_cpu = UINT_MAX;
- spin_unlock(&logbuf_lock);
+ /*
+ * Try to acquire and then immediately release the
+ * console semaphore. The release will do all the
+ * actual magic (print out buffers, wake up klogd,
+ * etc).
+ *
+ * The acquire_console_semaphore_for_printk() function
+ * will release 'logbuf_lock' regardless of whether it
+ * actually gets the semaphore or not.
+ */
+ if (acquire_console_semaphore_for_printk(this_cpu))
+ release_console_sem();
- /*
- * Console drivers may assume that per-cpu resources have
- * been allocated. So unless they're explicitly marked as
- * being able to cope (CON_ANYTIME) don't call them until
- * this CPU is officially up.
- */
- if (cpu_online(smp_processor_id()) || have_callable_console()) {
- console_may_schedule = 0;
- release_console_sem();
- } else {
- /* Release by hand to avoid flushing the buffer. */
- console_locked = 0;
- up(&console_sem);
- }
- lockdep_on();
- raw_local_irq_restore(flags);
- } else {
- /*
- * Someone else owns the drivers. We drop the spinlock, which
- * allows the semaphore holder to proceed and to call the
- * console drivers with the output which we just produced.
- */
- printk_cpu = UINT_MAX;
- spin_unlock(&logbuf_lock);
- lockdep_on();
+ lockdep_on();
out_restore_irqs:
- raw_local_irq_restore(flags);
- }
+ raw_local_irq_restore(flags);
preempt_enable();
return printed_len;
diff --git a/kernel/relay.c b/kernel/relay.c
index d080b9d161a7..d6204a485818 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -736,7 +736,7 @@ static int relay_file_open(struct inode *inode, struct file *filp)
kref_get(&buf->kref);
filp->private_data = buf;
- return 0;
+ return nonseekable_open(inode, filp);
}
/**
@@ -1056,6 +1056,10 @@ static struct pipe_buf_operations relay_pipe_buf_ops = {
.get = generic_pipe_buf_get,
};
+static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i)
+{
+}
+
/*
* subbuf_splice_actor - splice up to one subbuf's worth of data
*/
@@ -1066,7 +1070,7 @@ static int subbuf_splice_actor(struct file *in,
unsigned int flags,
int *nonpad_ret)
{
- unsigned int pidx, poff, total_len, subbuf_pages, ret;
+ unsigned int pidx, poff, total_len, subbuf_pages, nr_pages, ret;
struct rchan_buf *rbuf = in->private_data;
unsigned int subbuf_size = rbuf->chan->subbuf_size;
uint64_t pos = (uint64_t) *ppos;
@@ -1083,6 +1087,7 @@ static int subbuf_splice_actor(struct file *in,
.partial = partial,
.flags = flags,
.ops = &relay_pipe_buf_ops,
+ .spd_release = relay_page_release,
};
if (rbuf->subbufs_produced == rbuf->subbufs_consumed)
@@ -1097,8 +1102,9 @@ static int subbuf_splice_actor(struct file *in,
subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT;
pidx = (read_start / PAGE_SIZE) % subbuf_pages;
poff = read_start & ~PAGE_MASK;
+ nr_pages = min_t(unsigned int, subbuf_pages, PIPE_BUFFERS);
- for (total_len = 0; spd.nr_pages < subbuf_pages; spd.nr_pages++) {
+ for (total_len = 0; spd.nr_pages < nr_pages; spd.nr_pages++) {
unsigned int this_len, this_end, private;
unsigned int cur_pos = read_start + total_len;
diff --git a/kernel/sched.c b/kernel/sched.c
index 1cb53fb1fe3d..8dcdec6fe0fe 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -301,7 +301,7 @@ struct cfs_rq {
/* 'curr' points to currently running entity on this cfs_rq.
* It is set to NULL otherwise (i.e when none are currently running).
*/
- struct sched_entity *curr;
+ struct sched_entity *curr, *next;
unsigned long nr_spread_over;
@@ -594,18 +594,14 @@ enum {
SCHED_FEAT_NEW_FAIR_SLEEPERS = 1,
SCHED_FEAT_WAKEUP_PREEMPT = 2,
SCHED_FEAT_START_DEBIT = 4,
- SCHED_FEAT_TREE_AVG = 8,
- SCHED_FEAT_APPROX_AVG = 16,
- SCHED_FEAT_HRTICK = 32,
- SCHED_FEAT_DOUBLE_TICK = 64,
+ SCHED_FEAT_HRTICK = 8,
+ SCHED_FEAT_DOUBLE_TICK = 16,
};
const_debug unsigned int sysctl_sched_features =
SCHED_FEAT_NEW_FAIR_SLEEPERS * 1 |
SCHED_FEAT_WAKEUP_PREEMPT * 1 |
SCHED_FEAT_START_DEBIT * 1 |
- SCHED_FEAT_TREE_AVG * 0 |
- SCHED_FEAT_APPROX_AVG * 0 |
SCHED_FEAT_HRTICK * 1 |
SCHED_FEAT_DOUBLE_TICK * 0;
@@ -1056,6 +1052,49 @@ static void resched_cpu(int cpu)
resched_task(cpu_curr(cpu));
spin_unlock_irqrestore(&rq->lock, flags);
}
+
+#ifdef CONFIG_NO_HZ
+/*
+ * When add_timer_on() enqueues a timer into the timer wheel of an
+ * idle CPU then this timer might expire before the next timer event
+ * which is scheduled to wake up that CPU. In case of a completely
+ * idle system the next event might even be infinite time into the
+ * future. wake_up_idle_cpu() ensures that the CPU is woken up and
+ * leaves the inner idle loop so the newly added timer is taken into
+ * account when the CPU goes back to idle and evaluates the timer
+ * wheel for the next timer event.
+ */
+void wake_up_idle_cpu(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+
+ if (cpu == smp_processor_id())
+ return;
+
+ /*
+ * This is safe, as this function is called with the timer
+ * wheel base lock of (cpu) held. When the CPU is on the way
+ * to idle and has not yet set rq->curr to idle then it will
+ * be serialized on the timer wheel base lock and take the new
+ * timer into account automatically.
+ */
+ if (rq->curr != rq->idle)
+ return;
+
+ /*
+ * We can set TIF_RESCHED on the idle task of the other CPU
+ * lockless. The worst case is that the other CPU runs the
+ * idle task through an additional NOOP schedule()
+ */
+ set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED);
+
+ /* NEED_RESCHED must be visible before we test polling */
+ smp_mb();
+ if (!tsk_is_polling(rq->idle))
+ smp_send_reschedule(cpu);
+}
+#endif
+
#else
static void __resched_task(struct task_struct *p, int tif_bit)
{
@@ -1084,7 +1123,7 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
u64 tmp;
if (unlikely(!lw->inv_weight))
- lw->inv_weight = (WMULT_CONST - lw->weight/2) / lw->weight + 1;
+ lw->inv_weight = (WMULT_CONST-lw->weight/2) / (lw->weight+1);
tmp = (u64)delta_exec * weight;
/*
@@ -1108,11 +1147,13 @@ calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
lw->weight += inc;
+ lw->inv_weight = 0;
}
static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
{
lw->weight -= dec;
+ lw->inv_weight = 0;
}
/*
@@ -1394,6 +1435,12 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
{
s64 delta;
+ /*
+ * Buddy candidates are cache hot:
+ */
+ if (&p->se == cfs_rq_of(&p->se)->next)
+ return 1;
+
if (p->sched_class != &fair_sched_class)
return 0;
@@ -1853,10 +1900,11 @@ out_activate:
schedstat_inc(p, se.nr_wakeups_remote);
update_rq_clock(rq);
activate_task(rq, p, 1);
- check_preempt_curr(rq, p);
success = 1;
out_running:
+ check_preempt_curr(rq, p);
+
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
if (p->sched_class->task_wake_up)
@@ -1890,6 +1938,8 @@ static void __sched_fork(struct task_struct *p)
p->se.exec_start = 0;
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
+ p->se.last_wakeup = 0;
+ p->se.avg_overlap = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
@@ -3875,7 +3925,7 @@ need_resched_nonpreemptible:
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
- unlikely(signal_pending(prev)))) {
+ signal_pending(prev))) {
prev->state = TASK_RUNNING;
} else {
deactivate_task(rq, prev, 1);
@@ -4268,11 +4318,10 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
oldprio = p->prio;
on_rq = p->se.on_rq;
running = task_current(rq, p);
- if (on_rq) {
+ if (on_rq)
dequeue_task(rq, p, 0);
- if (running)
- p->sched_class->put_prev_task(rq, p);
- }
+ if (running)
+ p->sched_class->put_prev_task(rq, p);
if (rt_prio(prio))
p->sched_class = &rt_sched_class;
@@ -4281,10 +4330,9 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
p->prio = prio;
+ if (running)
+ p->sched_class->set_curr_task(rq);
if (on_rq) {
- if (running)
- p->sched_class->set_curr_task(rq);
-
enqueue_task(rq, p, 0);
check_class_changed(rq, p, prev_class, oldprio, running);
@@ -4581,19 +4629,17 @@ recheck:
update_rq_clock(rq);
on_rq = p->se.on_rq;
running = task_current(rq, p);
- if (on_rq) {
+ if (on_rq)
deactivate_task(rq, p, 0);
- if (running)
- p->sched_class->put_prev_task(rq, p);
- }
+ if (running)
+ p->sched_class->put_prev_task(rq, p);
oldprio = p->prio;
__setscheduler(rq, p, policy, param->sched_priority);
+ if (running)
+ p->sched_class->set_curr_task(rq);
if (on_rq) {
- if (running)
- p->sched_class->set_curr_task(rq);
-
activate_task(rq, p, 0);
check_class_changed(rq, p, prev_class, oldprio, running);
@@ -6804,6 +6850,10 @@ static int ndoms_cur; /* number of sched domains in 'doms_cur' */
*/
static cpumask_t fallback_doms;
+void __attribute__((weak)) arch_update_cpu_topology(void)
+{
+}
+
/*
* Set up scheduler domains and groups. Callers must hold the hotplug lock.
* For now this just excludes isolated cpus, but could be used to
@@ -6813,6 +6863,7 @@ static int arch_init_sched_domains(const cpumask_t *cpu_map)
{
int err;
+ arch_update_cpu_topology();
ndoms_cur = 1;
doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
if (!doms_cur)
@@ -6917,7 +6968,7 @@ match2:
}
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-static int arch_reinit_sched_domains(void)
+int arch_reinit_sched_domains(void)
{
int err;
@@ -7618,11 +7669,10 @@ void sched_move_task(struct task_struct *tsk)
running = task_current(rq, tsk);
on_rq = tsk->se.on_rq;
- if (on_rq) {
+ if (on_rq)
dequeue_task(rq, tsk, 0);
- if (unlikely(running))
- tsk->sched_class->put_prev_task(rq, tsk);
- }
+ if (unlikely(running))
+ tsk->sched_class->put_prev_task(rq, tsk);
set_task_rq(tsk, task_cpu(tsk));
@@ -7631,11 +7681,10 @@ void sched_move_task(struct task_struct *tsk)
tsk->sched_class->moved_group(tsk);
#endif
- if (on_rq) {
- if (unlikely(running))
- tsk->sched_class->set_curr_task(rq);
+ if (unlikely(running))
+ tsk->sched_class->set_curr_task(rq);
+ if (on_rq)
enqueue_task(rq, tsk, 0);
- }
task_rq_unlock(rq, &flags);
}
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 4b5e24cf2f4a..ef358ba07683 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -288,6 +288,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.exec_start);
PN(se.vruntime);
PN(se.sum_exec_runtime);
+ PN(se.avg_overlap);
nr_switches = p->nvcsw + p->nivcsw;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index e2a530515619..86a93376282c 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -73,13 +73,13 @@ unsigned int sysctl_sched_batch_wakeup_granularity = 10000000UL;
/*
* SCHED_OTHER wake-up granularity.
- * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)
*
* This option delays the preemption effects of decoupled workloads
* and reduces their over-scheduling. Synchronous workloads will still
* have immediate wakeup/sleep latencies.
*/
-unsigned int sysctl_sched_wakeup_granularity = 10000000UL;
+unsigned int sysctl_sched_wakeup_granularity = 5000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@@ -175,8 +175,15 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* Maintain a cache of leftmost tree entries (it is frequently
* used):
*/
- if (leftmost)
+ if (leftmost) {
cfs_rq->rb_leftmost = &se->run_node;
+ /*
+ * maintain cfs_rq->min_vruntime to be a monotonic increasing
+ * value tracking the leftmost vruntime in the tree.
+ */
+ cfs_rq->min_vruntime =
+ max_vruntime(cfs_rq->min_vruntime, se->vruntime);
+ }
rb_link_node(&se->run_node, parent, link);
rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
@@ -184,8 +191,24 @@ static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (cfs_rq->rb_leftmost == &se->run_node)
- cfs_rq->rb_leftmost = rb_next(&se->run_node);
+ if (cfs_rq->rb_leftmost == &se->run_node) {
+ struct rb_node *next_node;
+ struct sched_entity *next;
+
+ next_node = rb_next(&se->run_node);
+ cfs_rq->rb_leftmost = next_node;
+
+ if (next_node) {
+ next = rb_entry(next_node,
+ struct sched_entity, run_node);
+ cfs_rq->min_vruntime =
+ max_vruntime(cfs_rq->min_vruntime,
+ next->vruntime);
+ }
+ }
+
+ if (cfs_rq->next == se)
+ cfs_rq->next = NULL;
rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
}
@@ -260,12 +283,8 @@ static u64 __sched_period(unsigned long nr_running)
*/
static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- u64 slice = __sched_period(cfs_rq->nr_running);
-
- slice *= se->load.weight;
- do_div(slice, cfs_rq->load.weight);
-
- return slice;
+ return calc_delta_mine(__sched_period(cfs_rq->nr_running),
+ se->load.weight, &cfs_rq->load);
}
/*
@@ -283,11 +302,6 @@ static u64 __sched_vslice(unsigned long rq_weight, unsigned long nr_running)
return vslice;
}
-static u64 sched_vslice(struct cfs_rq *cfs_rq)
-{
- return __sched_vslice(cfs_rq->load.weight, cfs_rq->nr_running);
-}
-
static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
return __sched_vslice(cfs_rq->load.weight + se->load.weight,
@@ -303,7 +317,6 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
unsigned long delta_exec)
{
unsigned long delta_exec_weighted;
- u64 vruntime;
schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
@@ -315,19 +328,6 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
&curr->load);
}
curr->vruntime += delta_exec_weighted;
-
- /*
- * maintain cfs_rq->min_vruntime to be a monotonic increasing
- * value tracking the leftmost vruntime in the tree.
- */
- if (first_fair(cfs_rq)) {
- vruntime = min_vruntime(curr->vruntime,
- __pick_next_entity(cfs_rq)->vruntime);
- } else
- vruntime = curr->vruntime;
-
- cfs_rq->min_vruntime =
- max_vruntime(cfs_rq->min_vruntime, vruntime);
}
static void update_curr(struct cfs_rq *cfs_rq)
@@ -493,16 +493,11 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
{
u64 vruntime;
- vruntime = cfs_rq->min_vruntime;
-
- if (sched_feat(TREE_AVG)) {
- struct sched_entity *last = __pick_last_entity(cfs_rq);
- if (last) {
- vruntime += last->vruntime;
- vruntime >>= 1;
- }
- } else if (sched_feat(APPROX_AVG) && cfs_rq->nr_running)
- vruntime += sched_vslice(cfs_rq)/2;
+ if (first_fair(cfs_rq)) {
+ vruntime = min_vruntime(cfs_rq->min_vruntime,
+ __pick_next_entity(cfs_rq)->vruntime);
+ } else
+ vruntime = cfs_rq->min_vruntime;
/*
* The 'current' period is already promised to the current tasks,
@@ -515,8 +510,10 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
if (!initial) {
/* sleeps upto a single latency don't count. */
- if (sched_feat(NEW_FAIR_SLEEPERS))
- vruntime -= sysctl_sched_latency;
+ if (sched_feat(NEW_FAIR_SLEEPERS)) {
+ vruntime -= calc_delta_fair(sysctl_sched_latency,
+ &cfs_rq->load);
+ }
/* ensure we never gain time by being placed backwards. */
vruntime = max_vruntime(se->vruntime, vruntime);
@@ -545,6 +542,21 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
account_entity_enqueue(cfs_rq, se);
}
+static void update_avg(u64 *avg, u64 sample)
+{
+ s64 diff = sample - *avg;
+ *avg += diff >> 3;
+}
+
+static void update_avg_stats(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ if (!se->last_wakeup)
+ return;
+
+ update_avg(&se->avg_overlap, se->sum_exec_runtime - se->last_wakeup);
+ se->last_wakeup = 0;
+}
+
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
{
@@ -555,6 +567,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
update_stats_dequeue(cfs_rq, se);
if (sleep) {
+ update_avg_stats(cfs_rq, se);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
struct task_struct *tsk = task_of(se);
@@ -616,12 +629,32 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->prev_sum_exec_runtime = se->sum_exec_runtime;
}
+static struct sched_entity *
+pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ s64 diff, gran;
+
+ if (!cfs_rq->next)
+ return se;
+
+ diff = cfs_rq->next->vruntime - se->vruntime;
+ if (diff < 0)
+ return se;
+
+ gran = calc_delta_fair(sysctl_sched_wakeup_granularity, &cfs_rq->load);
+ if (diff > gran)
+ return se;
+
+ return cfs_rq->next;
+}
+
static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
{
struct sched_entity *se = NULL;
if (first_fair(cfs_rq)) {
se = __pick_next_entity(cfs_rq);
+ se = pick_next(cfs_rq, se);
set_next_entity(cfs_rq, se);
}
@@ -949,96 +982,121 @@ static inline int wake_idle(int cpu, struct task_struct *p)
#endif
#ifdef CONFIG_SMP
-static int select_task_rq_fair(struct task_struct *p, int sync)
+
+static const struct sched_class fair_sched_class;
+
+static int
+wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
+ struct task_struct *p, int prev_cpu, int this_cpu, int sync,
+ int idx, unsigned long load, unsigned long this_load,
+ unsigned int imbalance)
{
- int cpu, this_cpu;
- struct rq *rq;
- struct sched_domain *sd, *this_sd = NULL;
- int new_cpu;
+ struct task_struct *curr = this_rq->curr;
+ unsigned long tl = this_load;
+ unsigned long tl_per_task;
+
+ if (!(this_sd->flags & SD_WAKE_AFFINE))
+ return 0;
+
+ /*
+ * If the currently running task will sleep within
+ * a reasonable amount of time then attract this newly
+ * woken task:
+ */
+ if (sync && curr->sched_class == &fair_sched_class) {
+ if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
+ p->se.avg_overlap < sysctl_sched_migration_cost)
+ return 1;
+ }
+
+ schedstat_inc(p, se.nr_wakeups_affine_attempts);
+ tl_per_task = cpu_avg_load_per_task(this_cpu);
- cpu = task_cpu(p);
- rq = task_rq(p);
- this_cpu = smp_processor_id();
- new_cpu = cpu;
+ /*
+ * If sync wakeup then subtract the (maximum possible)
+ * effect of the currently running task from the load
+ * of the current CPU:
+ */
+ if (sync)
+ tl -= current->se.load.weight;
+
+ if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) ||
+ 100*(tl + p->se.load.weight) <= imbalance*load) {
+ /*
+ * This domain has SD_WAKE_AFFINE and
+ * p is cache cold in this domain, and
+ * there is no bad imbalance.
+ */
+ schedstat_inc(this_sd, ttwu_move_affine);
+ schedstat_inc(p, se.nr_wakeups_affine);
+
+ return 1;
+ }
+ return 0;
+}
- if (cpu == this_cpu)
- goto out_set_cpu;
+static int select_task_rq_fair(struct task_struct *p, int sync)
+{
+ struct sched_domain *sd, *this_sd = NULL;
+ int prev_cpu, this_cpu, new_cpu;
+ unsigned long load, this_load;
+ struct rq *rq, *this_rq;
+ unsigned int imbalance;
+ int idx;
+
+ prev_cpu = task_cpu(p);
+ rq = task_rq(p);
+ this_cpu = smp_processor_id();
+ this_rq = cpu_rq(this_cpu);
+ new_cpu = prev_cpu;
+ /*
+ * 'this_sd' is the first domain that both
+ * this_cpu and prev_cpu are present in:
+ */
for_each_domain(this_cpu, sd) {
- if (cpu_isset(cpu, sd->span)) {
+ if (cpu_isset(prev_cpu, sd->span)) {
this_sd = sd;
break;
}
}
if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))
- goto out_set_cpu;
+ goto out;
/*
* Check for affine wakeup and passive balancing possibilities.
*/
- if (this_sd) {
- int idx = this_sd->wake_idx;
- unsigned int imbalance;
- unsigned long load, this_load;
-
- imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
-
- load = source_load(cpu, idx);
- this_load = target_load(this_cpu, idx);
-
- new_cpu = this_cpu; /* Wake to this CPU if we can */
-
- if (this_sd->flags & SD_WAKE_AFFINE) {
- unsigned long tl = this_load;
- unsigned long tl_per_task;
-
- /*
- * Attract cache-cold tasks on sync wakeups:
- */
- if (sync && !task_hot(p, rq->clock, this_sd))
- goto out_set_cpu;
-
- schedstat_inc(p, se.nr_wakeups_affine_attempts);
- tl_per_task = cpu_avg_load_per_task(this_cpu);
-
- /*
- * If sync wakeup then subtract the (maximum possible)
- * effect of the currently running task from the load
- * of the current CPU:
- */
- if (sync)
- tl -= current->se.load.weight;
-
- if ((tl <= load &&
- tl + target_load(cpu, idx) <= tl_per_task) ||
- 100*(tl + p->se.load.weight) <= imbalance*load) {
- /*
- * This domain has SD_WAKE_AFFINE and
- * p is cache cold in this domain, and
- * there is no bad imbalance.
- */
- schedstat_inc(this_sd, ttwu_move_affine);
- schedstat_inc(p, se.nr_wakeups_affine);
- goto out_set_cpu;
- }
- }
+ if (!this_sd)
+ goto out;
- /*
- * Start passive balancing when half the imbalance_pct
- * limit is reached.
- */
- if (this_sd->flags & SD_WAKE_BALANCE) {
- if (imbalance*this_load <= 100*load) {
- schedstat_inc(this_sd, ttwu_move_balance);
- schedstat_inc(p, se.nr_wakeups_passive);
- goto out_set_cpu;
- }
+ idx = this_sd->wake_idx;
+
+ imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
+
+ load = source_load(prev_cpu, idx);
+ this_load = target_load(this_cpu, idx);
+
+ if (wake_affine(rq, this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,
+ load, this_load, imbalance))
+ return this_cpu;
+
+ if (prev_cpu == this_cpu)
+ goto out;
+
+ /*
+ * Start passive balancing when half the imbalance_pct
+ * limit is reached.
+ */
+ if (this_sd->flags & SD_WAKE_BALANCE) {
+ if (imbalance*this_load <= 100*load) {
+ schedstat_inc(this_sd, ttwu_move_balance);
+ schedstat_inc(p, se.nr_wakeups_passive);
+ return this_cpu;
}
}
- new_cpu = cpu; /* Could not wake to this_cpu. Wake to cpu instead */
-out_set_cpu:
+out:
return wake_idle(new_cpu, p);
}
#endif /* CONFIG_SMP */
@@ -1060,6 +1118,13 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
resched_task(curr);
return;
}
+
+ se->last_wakeup = se->sum_exec_runtime;
+ if (unlikely(se == pse))
+ return;
+
+ cfs_rq_of(pse)->next = pse;
+
/*
* Batch tasks do not preempt (their preemption is driven by
* the tick):
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 548c436a776b..7f60097d443a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -141,13 +141,8 @@ static void clocksource_watchdog(unsigned long data)
}
if (!list_empty(&watchdog_list)) {
- /* Cycle through CPUs to check if the CPUs stay synchronized to
- * each other. */
- int next_cpu = next_cpu(raw_smp_processor_id(), cpu_online_map);
- if (next_cpu >= NR_CPUS)
- next_cpu = first_cpu(cpu_online_map);
- watchdog_timer.expires += WATCHDOG_INTERVAL;
- add_timer_on(&watchdog_timer, next_cpu);
+ __mod_timer(&watchdog_timer,
+ watchdog_timer.expires + WATCHDOG_INTERVAL);
}
spin_unlock(&watchdog_lock);
}
@@ -169,7 +164,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
if (!started && watchdog) {
watchdog_last = watchdog->read();
watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
- add_timer_on(&watchdog_timer, first_cpu(cpu_online_map));
+ add_timer(&watchdog_timer);
}
} else {
if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
@@ -179,7 +174,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
if (watchdog)
del_timer(&watchdog_timer);
watchdog = cs;
- init_timer_deferrable(&watchdog_timer);
+ init_timer(&watchdog_timer);
watchdog_timer.function = clocksource_watchdog;
/* Reset watchdog cycles */
@@ -190,8 +185,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
watchdog_last = watchdog->read();
watchdog_timer.expires =
jiffies + WATCHDOG_INTERVAL;
- add_timer_on(&watchdog_timer,
- first_cpu(cpu_online_map));
+ add_timer(&watchdog_timer);
}
}
}
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 671af612b768..a3fa587c350c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -191,8 +191,12 @@ static void change_clocksource(void)
tick_clock_notify();
+ /*
+ * We're holding xtime lock and waking up klogd would deadlock
+ * us on enqueue. So no printing!
printk(KERN_INFO "Time: %s clocksource has been installed.\n",
clock->name);
+ */
}
#else
static inline void change_clocksource(void) { }
diff --git a/kernel/timer.c b/kernel/timer.c
index 99b00a25f88b..b024106daa70 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -451,10 +451,18 @@ void add_timer_on(struct timer_list *timer, int cpu)
spin_lock_irqsave(&base->lock, flags);
timer_set_base(timer, base);
internal_add_timer(base, timer);
+ /*
+ * Check whether the other CPU is idle and needs to be
+ * triggered to reevaluate the timer wheel when nohz is
+ * active. We are protected against the other CPU fiddling
+ * with the timer by holding the timer base lock. This also
+ * makes sure that a CPU on the way to idle can not evaluate
+ * the timer wheel.
+ */
+ wake_up_idle_cpu(cpu);
spin_unlock_irqrestore(&base->lock, flags);
}
-
/**
* mod_timer - modify a timer's timeout
* @timer: the timer to be modified
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.