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-rw-r--r--kernel/rcu/rcuperf.c5
-rw-r--r--kernel/rcu/rcutorture.c21
-rw-r--r--kernel/rcu/srcutiny.c9
-rw-r--r--kernel/rcu/srcutree.c32
-rw-r--r--kernel/rcu/tiny.c2
-rw-r--r--kernel/rcu/tree.c29
-rw-r--r--kernel/rcu/tree_exp.h4
-rw-r--r--kernel/rcu/tree_plugin.h44
8 files changed, 75 insertions, 71 deletions
diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index c29761152874..7a6890b23c5f 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -494,6 +494,10 @@ rcu_perf_cleanup(void)
if (torture_cleanup_begin())
return;
+ if (!cur_ops) {
+ torture_cleanup_end();
+ return;
+ }
if (reader_tasks) {
for (i = 0; i < nrealreaders; i++)
@@ -614,6 +618,7 @@ rcu_perf_init(void)
pr_cont("\n");
WARN_ON(!IS_MODULE(CONFIG_RCU_PERF_TEST));
firsterr = -EINVAL;
+ cur_ops = NULL;
goto unwind;
}
if (cur_ops->init)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index f14d1b18a74f..efaa5b3f4d3f 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -299,7 +299,6 @@ struct rcu_torture_ops {
int irq_capable;
int can_boost;
int extendables;
- int ext_irq_conflict;
const char *name;
};
@@ -592,12 +591,7 @@ static void srcu_torture_init(void)
static void srcu_torture_cleanup(void)
{
- static DEFINE_TORTURE_RANDOM(rand);
-
- if (torture_random(&rand) & 0x800)
- cleanup_srcu_struct(&srcu_ctld);
- else
- cleanup_srcu_struct_quiesced(&srcu_ctld);
+ cleanup_srcu_struct(&srcu_ctld);
srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
}
@@ -1160,7 +1154,7 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp)
unsigned long randmask2 = randmask1 >> 3;
WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT);
- /* Most of the time lots of bits, half the time only one bit. */
+ /* Mostly only one bit (need preemption!), sometimes lots of bits. */
if (!(randmask1 & 0x7))
mask = mask & randmask2;
else
@@ -1170,10 +1164,6 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp)
((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) ||
(!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH))))
mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
- if ((mask & RCUTORTURE_RDR_IRQ) &&
- !(mask & cur_ops->ext_irq_conflict) &&
- (oldmask & cur_ops->ext_irq_conflict))
- mask |= cur_ops->ext_irq_conflict; /* Or if readers object. */
return mask ?: RCUTORTURE_RDR_RCU;
}
@@ -1848,7 +1838,7 @@ static int rcutorture_oom_notify(struct notifier_block *self,
WARN(1, "%s invoked upon OOM during forward-progress testing.\n",
__func__);
rcu_torture_fwd_cb_hist();
- rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rcu_fwd_startat) / 2));
+ rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rcu_fwd_startat)) / 2);
WRITE_ONCE(rcu_fwd_emergency_stop, true);
smp_mb(); /* Emergency stop before free and wait to avoid hangs. */
pr_info("%s: Freed %lu RCU callbacks.\n",
@@ -2094,6 +2084,10 @@ rcu_torture_cleanup(void)
cur_ops->cb_barrier();
return;
}
+ if (!cur_ops) {
+ torture_cleanup_end();
+ return;
+ }
rcu_torture_barrier_cleanup();
torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task);
@@ -2267,6 +2261,7 @@ rcu_torture_init(void)
pr_cont("\n");
WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST));
firsterr = -EINVAL;
+ cur_ops = NULL;
goto unwind;
}
if (cur_ops->fqs == NULL && fqs_duration != 0) {
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 5d4a39a6505a..44d6606b8325 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -76,19 +76,16 @@ EXPORT_SYMBOL_GPL(init_srcu_struct);
* Must invoke this after you are finished using a given srcu_struct that
* was initialized via init_srcu_struct(), else you leak memory.
*/
-void _cleanup_srcu_struct(struct srcu_struct *ssp, bool quiesced)
+void cleanup_srcu_struct(struct srcu_struct *ssp)
{
WARN_ON(ssp->srcu_lock_nesting[0] || ssp->srcu_lock_nesting[1]);
- if (quiesced)
- WARN_ON(work_pending(&ssp->srcu_work));
- else
- flush_work(&ssp->srcu_work);
+ flush_work(&ssp->srcu_work);
WARN_ON(ssp->srcu_gp_running);
WARN_ON(ssp->srcu_gp_waiting);
WARN_ON(ssp->srcu_cb_head);
WARN_ON(&ssp->srcu_cb_head != ssp->srcu_cb_tail);
}
-EXPORT_SYMBOL_GPL(_cleanup_srcu_struct);
+EXPORT_SYMBOL_GPL(cleanup_srcu_struct);
/*
* Removes the count for the old reader from the appropriate element of
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index a60b8ba9e1ac..9b761e546de8 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -360,8 +360,14 @@ static unsigned long srcu_get_delay(struct srcu_struct *ssp)
return SRCU_INTERVAL;
}
-/* Helper for cleanup_srcu_struct() and cleanup_srcu_struct_quiesced(). */
-void _cleanup_srcu_struct(struct srcu_struct *ssp, bool quiesced)
+/**
+ * cleanup_srcu_struct - deconstruct a sleep-RCU structure
+ * @ssp: structure to clean up.
+ *
+ * Must invoke this after you are finished using a given srcu_struct that
+ * was initialized via init_srcu_struct(), else you leak memory.
+ */
+void cleanup_srcu_struct(struct srcu_struct *ssp)
{
int cpu;
@@ -369,24 +375,14 @@ void _cleanup_srcu_struct(struct srcu_struct *ssp, bool quiesced)
return; /* Just leak it! */
if (WARN_ON(srcu_readers_active(ssp)))
return; /* Just leak it! */
- if (quiesced) {
- if (WARN_ON(delayed_work_pending(&ssp->work)))
- return; /* Just leak it! */
- } else {
- flush_delayed_work(&ssp->work);
- }
+ flush_delayed_work(&ssp->work);
for_each_possible_cpu(cpu) {
struct srcu_data *sdp = per_cpu_ptr(ssp->sda, cpu);
- if (quiesced) {
- if (WARN_ON(timer_pending(&sdp->delay_work)))
- return; /* Just leak it! */
- if (WARN_ON(work_pending(&sdp->work)))
- return; /* Just leak it! */
- } else {
- del_timer_sync(&sdp->delay_work);
- flush_work(&sdp->work);
- }
+ del_timer_sync(&sdp->delay_work);
+ flush_work(&sdp->work);
+ if (WARN_ON(rcu_segcblist_n_cbs(&sdp->srcu_cblist)))
+ return; /* Forgot srcu_barrier(), so just leak it! */
}
if (WARN_ON(rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)) != SRCU_STATE_IDLE) ||
WARN_ON(srcu_readers_active(ssp))) {
@@ -397,7 +393,7 @@ void _cleanup_srcu_struct(struct srcu_struct *ssp, bool quiesced)
free_percpu(ssp->sda);
ssp->sda = NULL;
}
-EXPORT_SYMBOL_GPL(_cleanup_srcu_struct);
+EXPORT_SYMBOL_GPL(cleanup_srcu_struct);
/*
* Counts the new reader in the appropriate per-CPU element of the
diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 911bd9076d43..477b4eb44af5 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -52,7 +52,7 @@ void rcu_qs(void)
local_irq_save(flags);
if (rcu_ctrlblk.donetail != rcu_ctrlblk.curtail) {
rcu_ctrlblk.donetail = rcu_ctrlblk.curtail;
- raise_softirq(RCU_SOFTIRQ);
+ raise_softirq_irqoff(RCU_SOFTIRQ);
}
local_irq_restore(flags);
}
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 4cb1ebd93b0c..ec77ec336f58 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -144,7 +144,7 @@ static void sync_sched_exp_online_cleanup(int cpu);
/* rcuc/rcub kthread realtime priority */
static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0;
-module_param(kthread_prio, int, 0644);
+module_param(kthread_prio, int, 0444);
/* Delay in jiffies for grace-period initialization delays, debug only. */
@@ -401,7 +401,7 @@ static bool rcu_kick_kthreads;
*/
static ulong jiffies_till_sched_qs = ULONG_MAX;
module_param(jiffies_till_sched_qs, ulong, 0444);
-static ulong jiffies_to_sched_qs; /* Adjusted version of above if not default */
+static ulong jiffies_to_sched_qs; /* See adjust_jiffies_till_sched_qs(). */
module_param(jiffies_to_sched_qs, ulong, 0444); /* Display only! */
/*
@@ -419,6 +419,7 @@ static void adjust_jiffies_till_sched_qs(void)
WRITE_ONCE(jiffies_to_sched_qs, jiffies_till_sched_qs);
return;
}
+ /* Otherwise, set to third fqs scan, but bound below on large system. */
j = READ_ONCE(jiffies_till_first_fqs) +
2 * READ_ONCE(jiffies_till_next_fqs);
if (j < HZ / 10 + nr_cpu_ids / RCU_JIFFIES_FQS_DIV)
@@ -1202,7 +1203,7 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
static void rcu_gp_kthread_wake(void)
{
if ((current == rcu_state.gp_kthread &&
- !in_interrupt() && !in_serving_softirq()) ||
+ !in_irq() && !in_serving_softirq()) ||
!READ_ONCE(rcu_state.gp_flags) ||
!rcu_state.gp_kthread)
return;
@@ -1912,11 +1913,10 @@ rcu_report_qs_rdp(int cpu, struct rcu_data *rdp)
return;
}
mask = rdp->grpmask;
+ rdp->core_needs_qs = false;
if ((rnp->qsmask & mask) == 0) {
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
} else {
- rdp->core_needs_qs = false;
-
/*
* This GP can't end until cpu checks in, so all of our
* callbacks can be processed during the next GP.
@@ -2165,11 +2165,11 @@ void rcu_sched_clock_irq(int user)
}
/*
- * Scan the leaf rcu_node structures, processing dyntick state for any that
- * have not yet encountered a quiescent state, using the function specified.
- * Also initiate boosting for any threads blocked on the root rcu_node.
- *
- * The caller must have suppressed start of new grace periods.
+ * Scan the leaf rcu_node structures. For each structure on which all
+ * CPUs have reported a quiescent state and on which there are tasks
+ * blocking the current grace period, initiate RCU priority boosting.
+ * Otherwise, invoke the specified function to check dyntick state for
+ * each CPU that has not yet reported a quiescent state.
*/
static void force_qs_rnp(int (*f)(struct rcu_data *rdp))
{
@@ -3081,13 +3081,11 @@ static int rcu_pm_notify(struct notifier_block *self,
switch (action) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
- if (nr_cpu_ids <= 256) /* Expediting bad for large systems. */
- rcu_expedite_gp();
+ rcu_expedite_gp();
break;
case PM_POST_HIBERNATION:
case PM_POST_SUSPEND:
- if (nr_cpu_ids <= 256) /* Expediting bad for large systems. */
- rcu_unexpedite_gp();
+ rcu_unexpedite_gp();
break;
default:
break;
@@ -3264,8 +3262,7 @@ static void __init rcu_init_geometry(void)
jiffies_till_first_fqs = d;
if (jiffies_till_next_fqs == ULONG_MAX)
jiffies_till_next_fqs = d;
- if (jiffies_till_sched_qs == ULONG_MAX)
- adjust_jiffies_till_sched_qs();
+ adjust_jiffies_till_sched_qs();
/* If the compile-time values are accurate, just leave. */
if (rcu_fanout_leaf == RCU_FANOUT_LEAF &&
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 7be3e085ddd6..9c990df880d1 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -634,7 +634,7 @@ static void rcu_exp_handler(void *unused)
raw_spin_lock_irqsave_rcu_node(rnp, flags);
if (rnp->expmask & rdp->grpmask) {
rdp->deferred_qs = true;
- WRITE_ONCE(t->rcu_read_unlock_special.b.exp_hint, true);
+ t->rcu_read_unlock_special.b.exp_hint = true;
}
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
@@ -649,7 +649,7 @@ static void rcu_exp_handler(void *unused)
*
* If the CPU is fully enabled (or if some buggy RCU-preempt
* read-side critical section is being used from idle), just
- * invoke rcu_preempt_defer_qs() to immediately report the
+ * invoke rcu_preempt_deferred_qs() to immediately report the
* quiescent state. We cannot use rcu_read_unlock_special()
* because we are in an interrupt handler, which will cause that
* function to take an early exit without doing anything.
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index a1f9d7c15bd8..1102765f91fd 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -285,7 +285,7 @@ static void rcu_qs(void)
TPS("cpuqs"));
__this_cpu_write(rcu_data.cpu_no_qs.b.norm, false);
barrier(); /* Coordinate with rcu_flavor_sched_clock_irq(). */
- current->rcu_read_unlock_special.b.need_qs = false;
+ WRITE_ONCE(current->rcu_read_unlock_special.b.need_qs, false);
}
}
@@ -710,19 +710,25 @@ static void rcu_flavor_sched_clock_irq(int user)
/*
* Check for a task exiting while in a preemptible-RCU read-side
- * critical section, clean up if so. No need to issue warnings,
- * as debug_check_no_locks_held() already does this if lockdep
- * is enabled.
+ * critical section, clean up if so. No need to issue warnings, as
+ * debug_check_no_locks_held() already does this if lockdep is enabled.
+ * Besides, if this function does anything other than just immediately
+ * return, there was a bug of some sort. Spewing warnings from this
+ * function is like as not to simply obscure important prior warnings.
*/
void exit_rcu(void)
{
struct task_struct *t = current;
- if (likely(list_empty(&current->rcu_node_entry)))
+ if (unlikely(!list_empty(&current->rcu_node_entry))) {
+ t->rcu_read_lock_nesting = 1;
+ barrier();
+ WRITE_ONCE(t->rcu_read_unlock_special.b.blocked, true);
+ } else if (unlikely(t->rcu_read_lock_nesting)) {
+ t->rcu_read_lock_nesting = 1;
+ } else {
return;
- t->rcu_read_lock_nesting = 1;
- barrier();
- t->rcu_read_unlock_special.b.blocked = true;
+ }
__rcu_read_unlock();
rcu_preempt_deferred_qs(current);
}
@@ -1064,8 +1070,6 @@ static int rcu_boost_kthread(void *arg)
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
__releases(rnp->lock)
{
- struct task_struct *t;
-
raw_lockdep_assert_held_rcu_node(rnp);
if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks == NULL) {
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
@@ -1079,9 +1083,8 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
if (rnp->exp_tasks == NULL)
rnp->boost_tasks = rnp->gp_tasks;
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
- t = rnp->boost_kthread_task;
- if (t)
- rcu_wake_cond(t, rnp->boost_kthread_status);
+ rcu_wake_cond(rnp->boost_kthread_task,
+ rnp->boost_kthread_status);
} else {
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
@@ -1553,11 +1556,22 @@ static void rcu_cleanup_after_idle(void)
*/
-/* Parse the boot-time rcu_nocb_mask CPU list from the kernel parameters. */
+/*
+ * Parse the boot-time rcu_nocb_mask CPU list from the kernel parameters.
+ * The string after the "rcu_nocbs=" is either "all" for all CPUs, or a
+ * comma-separated list of CPUs and/or CPU ranges. If an invalid list is
+ * given, a warning is emitted and all CPUs are offloaded.
+ */
static int __init rcu_nocb_setup(char *str)
{
alloc_bootmem_cpumask_var(&rcu_nocb_mask);
- cpulist_parse(str, rcu_nocb_mask);
+ if (!strcasecmp(str, "all"))
+ cpumask_setall(rcu_nocb_mask);
+ else
+ if (cpulist_parse(str, rcu_nocb_mask)) {
+ pr_warn("rcu_nocbs= bad CPU range, all CPUs set\n");
+ cpumask_setall(rcu_nocb_mask);
+ }
return 1;
}
__setup("rcu_nocbs=", rcu_nocb_setup);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.