From 6b44f519017b219a12b37173c7eef8dfce2c0100 Mon Sep 17 00:00:00 2001 From: Scot Doyle Date: Sun, 24 Aug 2014 17:12:27 +0000 Subject: [PATCH] sched/wait: Document timeout corner case The timeout may elapse without 0 being returned, such as when waiting on an unused queue. Document this possibility. Signed-off-by: Scot Doyle Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Link: http://lkml.kernel.org/r/alpine.LNX.2.11.1408241710070.6462@localhost.localdomain Signed-off-by: Ingo Molnar --- include/linux/wait.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/include/linux/wait.h b/include/linux/wait.h index 6fb1ba5f9b2f..034f6fc7c65f 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -280,9 +280,11 @@ do { \ * wake_up() has to be called after changing any variable that could * change the result of the wait condition. * - * The function returns 0 if the @timeout elapsed, or the remaining - * jiffies (at least 1) if the @condition evaluated to %true before - * the @timeout elapsed. + * Returns: + * 0 if the @condition evaluated to %false after the @timeout elapsed, + * 1 if the @condition evaluated to %true after the @timeout elapsed, + * or the remaining jiffies (at least 1) if the @condition evaluated + * to %true before the @timeout elapsed. */ #define wait_event_timeout(wq, condition, timeout) \ ({ \ @@ -363,9 +365,11 @@ do { \ * change the result of the wait condition. * * Returns: - * 0 if the @timeout elapsed, -%ERESTARTSYS if it was interrupted by - * a signal, or the remaining jiffies (at least 1) if the @condition - * evaluated to %true before the @timeout elapsed. + * 0 if the @condition evaluated to %false after the @timeout elapsed, + * 1 if the @condition evaluated to %true after the @timeout elapsed, + * the remaining jiffies (at least 1) if the @condition evaluated + * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was + * interrupted by a signal. */ #define wait_event_interruptible_timeout(wq, condition, timeout) \ ({ \