From: Ankur Arora <[email protected]> Update comment in __cond_resched() clarifying how urgently needed quiescent state are provided.
Signed-off-by: Ankur Arora <[email protected]> Reviewed-by: Frederic Weisbecker <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/sched/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 95e40895a5190..b0f7ffcc46a66 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7281,7 +7281,7 @@ 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, @@ -7290,6 +7290,8 @@ 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(); -- 2.40.1
