2013-07-04 18:48:25

by Kirill Tkhai

Subject: [PATCH] sched, __wake_up_sync_key: Fix nr_exclusive tasks which lead to WF_SYNC clearing

The only one task can replace waker.

Signed-off-by: Kirill Tkhai <[email protected]>
CC: Steven Rostedt <[email protected]>
CC: Ingo Molnar <[email protected]>
CC: Peter Zijlstra <[email protected]>
---
kernel/sched/core.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9d06ad6..4ff7404 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2658,7 +2658,7 @@ void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
if (unlikely(!q))
return;

- if (unlikely(!nr_exclusive))
+ if (unlikely(nr_exclusive != 1))
wake_flags = 0;

spin_lock_irqsave(&q->lock, flags);

2013-07-05 10:28:55

by Peter Zijlstra

Subject: Re: [PATCH] sched, __wake_up_sync_key: Fix nr_exclusive tasks which lead to WF_SYNC clearing

On Thu, Jul 04, 2013 at 10:48:20PM +0400, Kirill Tkhai wrote:
> The only one task can replace waker.

Fair enough.. thanks!

2013-07-12 13:30:40

by tip-bot for Vasyl Gomonovych

Subject: [tip:sched/core] sched/__wake_up_sync_key(): Fix nr_exclusive tasks which lead to WF_SYNC clearing

Commit-ID: cedce3e730833d26a37826a96e1905b6ef387df9
Gitweb: http://git.kernel.org/tip/cedce3e730833d26a37826a96e1905b6ef387df9
Author: Kirill Tkhai <[email protected]>
AuthorDate: Thu, 4 Jul 2013 22:48:20 +0400
Committer: Ingo Molnar <[email protected]>
CommitDate: Fri, 12 Jul 2013 13:54:03 +0200

sched/__wake_up_sync_key(): Fix nr_exclusive tasks which lead to WF_SYNC clearing

Only one task can replace the waker.

Signed-off-by: Kirill Tkhai <[email protected]>
CC: Steven Rostedt <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0d8eb45..f737871 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2660,7 +2660,7 @@ void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
if (unlikely(!q))
return;

- if (unlikely(!nr_exclusive))
+ if (unlikely(nr_exclusive != 1))
wake_flags = 0;

spin_lock_irqsave(&q->lock, flags);