From b3212fe2bc06fa1014b3063b85b2bac4332a1c28 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 21 Mar 2020 12:25:59 +0100 Subject: [PATCH] sched/swait: Prepare usage in completions As a preparation to use simple wait queues for completions: - Provide swake_up_all_locked() to support complete_all() - Make __prepare_to_swait() public available This is done to enable the usage of complete() within truly atomic contexts on a PREEMPT_RT enabled kernel. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200321113242.228481202@linutronix.de --- kernel/sched/sched.h | 3 +++ kernel/sched/swait.c | 15 ++++++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 9ea647835fd6..fdc77e796324 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2492,3 +2492,6 @@ static inline bool is_per_cpu_kthread(struct task_struct *p) return true; } #endif + +void swake_up_all_locked(struct swait_queue_head *q); +void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c index e83a3f8449f6..e1c655f928c7 100644 --- a/kernel/sched/swait.c +++ b/kernel/sched/swait.c @@ -32,6 +32,19 @@ void swake_up_locked(struct swait_queue_head *q) } EXPORT_SYMBOL(swake_up_locked); +/* + * Wake up all waiters. This is an interface which is solely exposed for + * completions and not for general usage. + * + * It is intentionally different from swake_up_all() to allow usage from + * hard interrupt context and interrupt disabled regions. + */ +void swake_up_all_locked(struct swait_queue_head *q) +{ + while (!list_empty(&q->task_list)) + swake_up_locked(q); +} + void swake_up_one(struct swait_queue_head *q) { unsigned long flags; @@ -69,7 +82,7 @@ void swake_up_all(struct swait_queue_head *q) } EXPORT_SYMBOL(swake_up_all); -static void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait) +void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait) { wait->task = current; if (list_empty(&wait->task_list))