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-rw-r--r--kernel/sched/core.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 165c90ba64ea..d328707626e3 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7289,7 +7289,7 @@ int __sched __cond_resched(void)
return 1;
}
/*
- * In preemptible kernels, ->rcu_read_lock_nesting tells the tick
+ * In PREEMPT_RCU kernels, ->rcu_read_lock_nesting tells the tick
* whether the current CPU is in an RCU read-side critical section,
* so the tick can report quiescent states even for CPUs looping
* in kernel context. In contrast, in non-preemptible kernels,
@@ -7298,6 +7298,8 @@ int __sched __cond_resched(void)
* RCU quiescent state. Therefore, the following code causes
* cond_resched() to report a quiescent state, but only when RCU
* is in urgent need of one.
+ * A third case, preemptible, but non-PREEMPT_RCU provides for
+ * urgently needed quiescent states via rcu_flavor_sched_clock_irq().
*/
#ifndef CONFIG_PREEMPT_RCU
rcu_all_qs();