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-rw-r--r--kernel/rcu/rcutorture.c7
-rw-r--r--kernel/rcu/srcutiny.c14
-rw-r--r--kernel/rcu/tasks.h5
-rw-r--r--kernel/rcu/tiny.c17
-rw-r--r--kernel/rcu/tree.c46
-rw-r--r--kernel/rcu/tree_exp.h4
-rw-r--r--kernel/rcu/tree_nocb.h10
-rw-r--r--kernel/rcu/tree_plugin.h26
-rw-r--r--kernel/rcu/tree_stall.h5
9 files changed, 88 insertions, 46 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 91103279d7b4..503c2aa845a4 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -750,6 +750,9 @@ static struct rcu_torture_ops srcud_ops = {
.deferred_free = srcu_torture_deferred_free,
.sync = srcu_torture_synchronize,
.exp_sync = srcu_torture_synchronize_expedited,
+ .get_gp_state = srcu_torture_get_gp_state,
+ .start_gp_poll = srcu_torture_start_gp_poll,
+ .poll_gp_state = srcu_torture_poll_gp_state,
.call = srcu_torture_call,
.cb_barrier = srcu_torture_barrier,
.stats = srcu_torture_stats,
@@ -2803,12 +2806,12 @@ static int rcutorture_oom_notify(struct notifier_block *self,
for (i = 0; i < fwd_progress; i++)
ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
- rcu_barrier();
+ cur_ops->cb_barrier();
ncbs = 0;
for (i = 0; i < fwd_progress; i++)
ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
- rcu_barrier();
+ cur_ops->cb_barrier();
ncbs = 0;
for (i = 0; i < fwd_progress; i++)
ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 92c002d65482..33adafdad261 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -117,7 +117,7 @@ void srcu_drive_gp(struct work_struct *wp)
struct srcu_struct *ssp;
ssp = container_of(wp, struct srcu_struct, srcu_work);
- if (ssp->srcu_gp_running || USHORT_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
+ if (ssp->srcu_gp_running || ULONG_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
return; /* Already running or nothing to do. */
/* Remove recently arrived callbacks and wait for readers. */
@@ -150,17 +150,17 @@ void srcu_drive_gp(struct work_struct *wp)
* straighten that out.
*/
WRITE_ONCE(ssp->srcu_gp_running, false);
- if (USHORT_CMP_LT(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
+ if (ULONG_CMP_LT(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)))
schedule_work(&ssp->srcu_work);
}
EXPORT_SYMBOL_GPL(srcu_drive_gp);
static void srcu_gp_start_if_needed(struct srcu_struct *ssp)
{
- unsigned short cookie;
+ unsigned long cookie;
cookie = get_state_synchronize_srcu(ssp);
- if (USHORT_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie))
+ if (ULONG_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie))
return;
WRITE_ONCE(ssp->srcu_idx_max, cookie);
if (!READ_ONCE(ssp->srcu_gp_running)) {
@@ -215,7 +215,7 @@ unsigned long get_state_synchronize_srcu(struct srcu_struct *ssp)
barrier();
ret = (READ_ONCE(ssp->srcu_idx) + 3) & ~0x1;
barrier();
- return ret & USHRT_MAX;
+ return ret;
}
EXPORT_SYMBOL_GPL(get_state_synchronize_srcu);
@@ -240,10 +240,10 @@ EXPORT_SYMBOL_GPL(start_poll_synchronize_srcu);
*/
bool poll_state_synchronize_srcu(struct srcu_struct *ssp, unsigned long cookie)
{
- bool ret = USHORT_CMP_GE(READ_ONCE(ssp->srcu_idx), cookie);
+ unsigned long cur_s = READ_ONCE(ssp->srcu_idx);
barrier();
- return ret;
+ return ULONG_CMP_GE(cur_s, cookie) || ULONG_CMP_LT(cur_s, cookie - 3);
}
EXPORT_SYMBOL_GPL(poll_state_synchronize_srcu);
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 83c7e6620d40..f5bf6fb430da 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -560,7 +560,7 @@ static int __noreturn rcu_tasks_kthread(void *arg)
static void synchronize_rcu_tasks_generic(struct rcu_tasks *rtp)
{
/* Complain if the scheduler has not started. */
- RCU_LOCKDEP_WARN(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE,
+ WARN_ONCE(rcu_scheduler_active == RCU_SCHEDULER_INACTIVE,
"synchronize_rcu_tasks called too soon");
// If the grace-period kthread is running, use it.
@@ -1500,6 +1500,7 @@ static void rcu_tasks_trace_pregp_step(struct list_head *hop)
if (rcu_tasks_trace_pertask_prep(t, true))
trc_add_holdout(t, hop);
rcu_read_unlock();
+ cond_resched_tasks_rcu_qs();
}
// Only after all running tasks have been accounted for is it
@@ -1520,6 +1521,7 @@ static void rcu_tasks_trace_pregp_step(struct list_head *hop)
raw_spin_lock_irqsave_rcu_node(rtpcp, flags);
}
raw_spin_unlock_irqrestore_rcu_node(rtpcp, flags);
+ cond_resched_tasks_rcu_qs();
}
// Re-enable CPU hotplug now that the holdout list is populated.
@@ -1619,6 +1621,7 @@ static void check_all_holdout_tasks_trace(struct list_head *hop,
trc_del_holdout(t);
else if (needreport)
show_stalled_task_trace(t, firstreport);
+ cond_resched_tasks_rcu_qs();
}
// Re-enable CPU hotplug now that the holdout list scan has completed.
diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 435edc785412..a33a8d4942c3 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -158,6 +158,10 @@ void synchronize_rcu(void)
}
EXPORT_SYMBOL_GPL(synchronize_rcu);
+static void tiny_rcu_leak_callback(struct rcu_head *rhp)
+{
+}
+
/*
* Post an RCU callback to be invoked after the end of an RCU grace
* period. But since we have but one CPU, that would be after any
@@ -165,9 +169,20 @@ EXPORT_SYMBOL_GPL(synchronize_rcu);
*/
void call_rcu(struct rcu_head *head, rcu_callback_t func)
{
+ static atomic_t doublefrees;
unsigned long flags;
- debug_rcu_head_queue(head);
+ if (debug_rcu_head_queue(head)) {
+ if (atomic_inc_return(&doublefrees) < 4) {
+ pr_err("%s(): Double-freed CB %p->%pS()!!! ", __func__, head, head->func);
+ mem_dump_obj(head);
+ }
+
+ if (!__is_kvfree_rcu_offset((unsigned long)head->func))
+ WRITE_ONCE(head->func, tiny_rcu_leak_callback);
+ return;
+ }
+
head->func = func;
head->next = NULL;
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index ef15bae3c7c7..6bb8e72bc815 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2344,8 +2344,8 @@ void rcu_sched_clock_irq(int user)
rcu_flavor_sched_clock_irq(user);
if (rcu_pending(user))
invoke_rcu_core();
- if (user)
- rcu_tasks_classic_qs(current, false);
+ if (user || rcu_is_cpu_rrupt_from_idle())
+ rcu_note_voluntary_context_switch(current);
lockdep_assert_irqs_disabled();
trace_rcu_utilization(TPS("End scheduler-tick"));
@@ -2835,7 +2835,7 @@ EXPORT_SYMBOL_GPL(call_rcu);
/* Maximum number of jiffies to wait before draining a batch. */
-#define KFREE_DRAIN_JIFFIES (HZ / 50)
+#define KFREE_DRAIN_JIFFIES (5 * HZ)
#define KFREE_N_BATCHES 2
#define FREE_N_CHANNELS 2
@@ -3096,6 +3096,21 @@ need_offload_krc(struct kfree_rcu_cpu *krcp)
return !!krcp->head;
}
+static void
+schedule_delayed_monitor_work(struct kfree_rcu_cpu *krcp)
+{
+ long delay, delay_left;
+
+ delay = READ_ONCE(krcp->count) >= KVFREE_BULK_MAX_ENTR ? 1:KFREE_DRAIN_JIFFIES;
+ if (delayed_work_pending(&krcp->monitor_work)) {
+ delay_left = krcp->monitor_work.timer.expires - jiffies;
+ if (delay < delay_left)
+ mod_delayed_work(system_wq, &krcp->monitor_work, delay);
+ return;
+ }
+ queue_delayed_work(system_wq, &krcp->monitor_work, delay);
+}
+
/*
* This function is invoked after the KFREE_DRAIN_JIFFIES timeout.
*/
@@ -3153,7 +3168,7 @@ static void kfree_rcu_monitor(struct work_struct *work)
// work to repeat an attempt. Because previous batches are
// still in progress.
if (need_offload_krc(krcp))
- schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
+ schedule_delayed_monitor_work(krcp);
raw_spin_unlock_irqrestore(&krcp->lock, flags);
}
@@ -3186,15 +3201,16 @@ static void fill_page_cache_func(struct work_struct *work)
bnode = (struct kvfree_rcu_bulk_data *)
__get_free_page(GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
- if (bnode) {
- raw_spin_lock_irqsave(&krcp->lock, flags);
- pushed = put_cached_bnode(krcp, bnode);
- raw_spin_unlock_irqrestore(&krcp->lock, flags);
+ if (!bnode)
+ break;
- if (!pushed) {
- free_page((unsigned long) bnode);
- break;
- }
+ raw_spin_lock_irqsave(&krcp->lock, flags);
+ pushed = put_cached_bnode(krcp, bnode);
+ raw_spin_unlock_irqrestore(&krcp->lock, flags);
+
+ if (!pushed) {
+ free_page((unsigned long) bnode);
+ break;
}
}
@@ -3341,7 +3357,7 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
// Set timer to drain after KFREE_DRAIN_JIFFIES.
if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING)
- schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
+ schedule_delayed_monitor_work(krcp);
unlock_return:
krc_this_cpu_unlock(krcp, flags);
@@ -3374,7 +3390,7 @@ kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
atomic_set(&krcp->backoff_page_cache_fill, 1);
}
- return count;
+ return count == 0 ? SHRINK_EMPTY : count;
}
static unsigned long
@@ -3417,7 +3433,7 @@ void __init kfree_rcu_scheduler_running(void)
raw_spin_lock_irqsave(&krcp->lock, flags);
if (need_offload_krc(krcp))
- schedule_delayed_work_on(cpu, &krcp->monitor_work, KFREE_DRAIN_JIFFIES);
+ schedule_delayed_monitor_work(krcp);
raw_spin_unlock_irqrestore(&krcp->lock, flags);
}
}
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 54e05d13d151..18e9b4cd78ef 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -828,11 +828,13 @@ static void rcu_exp_handler(void *unused)
{
struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
struct rcu_node *rnp = rdp->mynode;
+ bool preempt_bh_enabled = !(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK));
if (!(READ_ONCE(rnp->expmask) & rdp->grpmask) ||
__this_cpu_read(rcu_data.cpu_no_qs.b.exp))
return;
- if (rcu_is_cpu_rrupt_from_idle()) {
+ if (rcu_is_cpu_rrupt_from_idle() ||
+ (IS_ENABLED(CONFIG_PREEMPT_COUNT) && preempt_bh_enabled)) {
rcu_report_exp_rdp(this_cpu_ptr(&rcu_data));
return;
}
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index a8f574d8850d..0a5f0ef41484 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1111,7 +1111,7 @@ int rcu_nocb_cpu_deoffload(int cpu)
if (!ret)
cpumask_clear_cpu(cpu, rcu_nocb_mask);
} else {
- pr_info("NOCB: Can't CB-deoffload an offline CPU\n");
+ pr_info("NOCB: Cannot CB-deoffload offline CPU %d\n", rdp->cpu);
ret = -EINVAL;
}
}
@@ -1196,7 +1196,7 @@ int rcu_nocb_cpu_offload(int cpu)
if (!ret)
cpumask_set_cpu(cpu, rcu_nocb_mask);
} else {
- pr_info("NOCB: Can't CB-offload an offline CPU\n");
+ pr_info("NOCB: Cannot CB-offload offline CPU %d\n", rdp->cpu);
ret = -EINVAL;
}
}
@@ -1452,8 +1452,8 @@ static void show_rcu_nocb_gp_state(struct rcu_data *rdp)
(long)rdp->nocb_gp_seq,
rnp->grplo, rnp->grphi, READ_ONCE(rdp->nocb_gp_loops),
rdp->nocb_gp_kthread ? task_state_to_char(rdp->nocb_gp_kthread) : '.',
- rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1,
- show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread));
+ rdp->nocb_gp_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1,
+ show_rcu_should_be_on_cpu(rdp->nocb_gp_kthread));
}
/* Dump out nocb kthread state for the specified rcu_data structure. */
@@ -1497,7 +1497,7 @@ static void show_rcu_nocb_state(struct rcu_data *rdp)
".B"[!!rcu_cblist_n_cbs(&rdp->nocb_bypass)],
rcu_segcblist_n_cbs(&rdp->cblist),
rdp->nocb_cb_kthread ? task_state_to_char(rdp->nocb_cb_kthread) : '.',
- rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_gp_kthread) : -1,
+ rdp->nocb_cb_kthread ? (int)task_cpu(rdp->nocb_cb_kthread) : -1,
show_rcu_should_be_on_cpu(rdp->nocb_cb_kthread));
/* It is OK for GP kthreads to have GP state. */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 438ecae6bd7e..e3142ee35fc6 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -641,7 +641,8 @@ static void rcu_read_unlock_special(struct task_struct *t)
expboost = (t->rcu_blocked_node && READ_ONCE(t->rcu_blocked_node->exp_tasks)) ||
(rdp->grpmask & READ_ONCE(rnp->expmask)) ||
- IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) ||
+ (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) &&
+ ((rdp->grpmask & READ_ONCE(rnp->qsmask)) || t->rcu_blocked_node)) ||
(IS_ENABLED(CONFIG_RCU_BOOST) && irqs_were_disabled &&
t->rcu_blocked_node);
// Need to defer quiescent state until everything is enabled.
@@ -718,9 +719,6 @@ static void rcu_flavor_sched_clock_irq(int user)
struct task_struct *t = current;
lockdep_assert_irqs_disabled();
- if (user || rcu_is_cpu_rrupt_from_idle()) {
- rcu_note_voluntary_context_switch(current);
- }
if (rcu_preempt_depth() > 0 ||
(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK))) {
/* No QS, force context switch if deferred. */
@@ -824,6 +822,7 @@ void rcu_read_unlock_strict(void)
if (irqs_disabled() || preempt_count() || !rcu_state.gp_kthread)
return;
rdp = this_cpu_ptr(&rcu_data);
+ rdp->cpu_no_qs.b.norm = false;
rcu_report_qs_rdp(rdp);
udelay(rcu_unlock_delay);
}
@@ -869,7 +868,7 @@ void rcu_all_qs(void)
if (!raw_cpu_read(rcu_data.rcu_urgent_qs))
return;
- preempt_disable();
+ preempt_disable(); // For CONFIG_PREEMPT_COUNT=y kernels
/* Load rcu_urgent_qs before other flags. */
if (!smp_load_acquire(this_cpu_ptr(&rcu_data.rcu_urgent_qs))) {
preempt_enable();
@@ -931,10 +930,13 @@ static notrace bool rcu_preempt_need_deferred_qs(struct task_struct *t)
return false;
}
-// Except that we do need to respond to a request by an expedited grace
-// period for a quiescent state from this CPU. Note that requests from
-// tasks are handled when removing the task from the blocked-tasks list
-// below.
+// Except that we do need to respond to a request by an expedited
+// grace period for a quiescent state from this CPU. Note that in
+// non-preemptible kernels, there can be no context switches within RCU
+// read-side critical sections, which in turn means that the leaf rcu_node
+// structure's blocked-tasks list is always empty. is therefore no need to
+// actually check it. Instead, a quiescent state from this CPU suffices,
+// and this function is only called from such a quiescent state.
notrace void rcu_preempt_deferred_qs(struct task_struct *t)
{
struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
@@ -972,7 +974,6 @@ static void rcu_flavor_sched_clock_irq(int user)
* neither access nor modify, at least not while the
* corresponding CPU is online.
*/
-
rcu_qs();
}
}
@@ -1238,8 +1239,11 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
cpu != outgoingcpu)
cpumask_set_cpu(cpu, cm);
cpumask_and(cm, cm, housekeeping_cpumask(HK_TYPE_RCU));
- if (cpumask_empty(cm))
+ if (cpumask_empty(cm)) {
cpumask_copy(cm, housekeeping_cpumask(HK_TYPE_RCU));
+ if (outgoingcpu >= 0)
+ cpumask_clear_cpu(outgoingcpu, cm);
+ }
set_cpus_allowed_ptr(t, cm);
mutex_unlock(&rnp->boost_kthread_mutex);
free_cpumask_var(cm);
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index c3fbbcc09327..5653560573e2 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -368,7 +368,7 @@ static void rcu_dump_cpu_stacks(void)
if (rnp->qsmask & leaf_node_cpu_bit(rnp, cpu)) {
if (cpu_is_offline(cpu))
pr_err("Offline CPU %d blocking current GP.\n", cpu);
- else if (!trigger_single_cpu_backtrace(cpu))
+ else
dump_cpu_task(cpu);
}
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
@@ -511,8 +511,7 @@ static void rcu_check_gp_kthread_starvation(void)
pr_err("RCU GP kthread last ran on offline CPU %d.\n", cpu);
} else {
pr_err("Stack dump where RCU GP kthread last ran:\n");
- if (!trigger_single_cpu_backtrace(cpu))
- dump_cpu_task(cpu);
+ dump_cpu_task(cpu);
}
}
wake_up_process(gpk);
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-05 19:45:58 +0300