* [PATCH 0/1] sched/wait: wait_event*_timeout() needs ___wait_cond_timeout() too
@ 2013-10-07 18:30 Oleg Nesterov
2013-10-07 18:31 ` [PATCH 1/1] " Oleg Nesterov
0 siblings, 1 reply; 3+ messages in thread
From: Oleg Nesterov @ 2013-10-07 18:30 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: Paul McKenney, Linus Torvalds, Thomas Gleixner, Andrew Morton,
linux-kernel
And another patch we already discussed.
wait_event_timeout(wq, true, 0) still returns 0, this doesn't look
right, and this doesn't match __wait_event_timeout(timeout => 0).
Sure, most probably nobody uses the constant timeout == 0, but this
can break the code which does something like
if (nonblock)
timeout = 0;
else
timeout = TIMEOUT;
success = wait_event_timeout(wq, CONDITION, timeout);
Oleg.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/1] sched/wait: wait_event*_timeout() needs ___wait_cond_timeout() too
2013-10-07 18:30 [PATCH 0/1] sched/wait: wait_event*_timeout() needs ___wait_cond_timeout() too Oleg Nesterov
@ 2013-10-07 18:31 ` Oleg Nesterov
2013-10-17 16:49 ` [tip:sched/core] sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too tip-bot for Oleg Nesterov
0 siblings, 1 reply; 3+ messages in thread
From: Oleg Nesterov @ 2013-10-07 18:31 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra
Cc: Paul McKenney, Linus Torvalds, Thomas Gleixner, Andrew Morton,
linux-kernel
Commit 4c663cfc ("wait: fix false timeouts when using
wait_event_timeout()") introduced the additional condition checks
after a timeout but only in the "slow" __wait*() paths.
wait_event_timeout(wq, CONDITION, 0) still returns 0 if CONDITION
is already true and we do not call __wait*().
Now that we have ___wait_cond_timeout() we can use it instead to
ensure that __ret will be properly updated.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
include/linux/wait.h | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/wait.h b/include/linux/wait.h
index ff9e20f..ec099b0 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -273,7 +273,7 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
@@ -331,7 +331,7 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
__ret; \
@@ -772,7 +772,7 @@ do { \
timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_lock_irq_timeout( \
wq, condition, lock, timeout); \
__ret; \
--
1.5.5.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [tip:sched/core] sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too
2013-10-07 18:31 ` [PATCH 1/1] " Oleg Nesterov
@ 2013-10-17 16:49 ` tip-bot for Oleg Nesterov
0 siblings, 0 replies; 3+ messages in thread
From: tip-bot for Oleg Nesterov @ 2013-10-17 16:49 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, peterz, oleg, tglx
Commit-ID: 8922915b38cd8b72f8e5af614b95be71d1d299d4
Gitweb: http://git.kernel.org/tip/8922915b38cd8b72f8e5af614b95be71d1d299d4
Author: Oleg Nesterov <oleg@redhat.com>
AuthorDate: Mon, 7 Oct 2013 20:31:06 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 16 Oct 2013 14:22:17 +0200
sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too
Commit 4c663cfc ("wait: fix false timeouts when using
wait_event_timeout()") introduced the additional condition checks
after a timeout but only in the "slow" __wait*() paths.
wait_event_timeout(wq, CONDITION, 0) still returns 0 if CONDITION
is already true and we do not call __wait*().
Now that we have ___wait_cond_timeout() we can use it instead to
ensure that __ret will be properly updated.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131007183106.GA10973@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/wait.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/wait.h b/include/linux/wait.h
index a2726c7..04c0260 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -270,7 +270,7 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
@@ -328,7 +328,7 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
__ret; \
@@ -769,7 +769,7 @@ do { \
timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_lock_irq_timeout( \
wq, condition, lock, timeout); \
__ret; \
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-10-17 16:50 UTC | newest]
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2013-10-07 18:30 [PATCH 0/1] sched/wait: wait_event*_timeout() needs ___wait_cond_timeout() too Oleg Nesterov
2013-10-07 18:31 ` [PATCH 1/1] " Oleg Nesterov
2013-10-17 16:49 ` [tip:sched/core] sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too tip-bot for Oleg Nesterov
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