From f6239d3f8ce4ebc5a5cfa3657377bd5007ae1547 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Tue, 23 May 2023 10:09:24 -0700 Subject: [PATCH] rcuwait: Support timeouts The rcuwait utility provides an efficient and safe single wait/wake mechanism. It is used in situations where queued wait is the wrong semantics, and often too bulky. For example, cases where the wait is already done under a lock. In the past, rcuwait has been extended to support beyond only uninterruptible sleep, and similarly, there are users that can benefit for the addition of timeouts. As such, tntroduce rcuwait_wait_event_timeout(), with semantics equivalent to calls for queued wait counterparts. Acked-by: Peter Zijlstra (Intel) Signed-off-by: Davidlohr Bueso Link: https://lore.kernel.org/r/20230523170927.20685-2-dave@stgolabs.net Signed-off-by: Dan Williams --- include/linux/rcuwait.h | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/include/linux/rcuwait.h b/include/linux/rcuwait.h index 8052d34da782..27343424225c 100644 --- a/include/linux/rcuwait.h +++ b/include/linux/rcuwait.h @@ -49,9 +49,9 @@ static inline void prepare_to_rcuwait(struct rcuwait *w) extern void finish_rcuwait(struct rcuwait *w); -#define rcuwait_wait_event(w, condition, state) \ +#define ___rcuwait_wait_event(w, condition, state, ret, cmd) \ ({ \ - int __ret = 0; \ + long __ret = ret; \ prepare_to_rcuwait(w); \ for (;;) { \ /* \ @@ -67,10 +67,27 @@ extern void finish_rcuwait(struct rcuwait *w); break; \ } \ \ - schedule(); \ + cmd; \ } \ finish_rcuwait(w); \ __ret; \ }) +#define rcuwait_wait_event(w, condition, state) \ + ___rcuwait_wait_event(w, condition, state, 0, schedule()) + +#define __rcuwait_wait_event_timeout(w, condition, state, timeout) \ + ___rcuwait_wait_event(w, ___wait_cond_timeout(condition), \ + state, timeout, \ + __ret = schedule_timeout(__ret)) + +#define rcuwait_wait_event_timeout(w, condition, state, timeout) \ +({ \ + long __ret = timeout; \ + if (!___wait_cond_timeout(condition)) \ + __ret = __rcuwait_wait_event_timeout(w, condition, \ + state, timeout); \ + __ret; \ +}) + #endif /* _LINUX_RCUWAIT_H_ */ -- 2.11.0