From: "T.Zhou" <t1zhou@163.com>
To: peterz@infradead.org
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: [PATCH] sched: Assign !p->on_cpu to the second parameter of smp_cond_load_acquire()
Date: Fri, 1 Jul 2016 11:08:01 +0800 [thread overview]
Message-ID: <20160701030801.GA15593@root> (raw)
The second parameter of smp_cond_load_acquire() should be !p->on_cpu
cause remote wakeup need to ensure that: if the task is running on
prev cpu, it should be descheduled before doing the actual wakeup.
Signed-off-by: T.Zhou <t1zhou@163.com>
---
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 3387e4f..8e6fef6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2047,7 +2047,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
* This ensures that tasks getting woken will be fully ordered against
* their previous state and preserve Program Order.
*/
- smp_cond_load_acquire(&p->on_cpu, !VAL);
+ smp_cond_load_acquire(&p->on_cpu, !p->on_cpu);
p->sched_contributes_to_load = !!task_contributes_to_load(p);
p->state = TASK_WAKING;
--
2.7.3
next reply other threads:[~2016-07-01 3:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-01 3:08 T.Zhou [this message]
2016-07-01 6:55 ` [PATCH] sched: Assign !p->on_cpu to the second parameter of smp_cond_load_acquire() Peter Zijlstra
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