From: Con Kolivas <kernel@kolivas.org>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Alfred Chen <cchalpha@gmail.com>, Ingo Molnar <mingo@redhat.com>
Subject: [PATCH] sched: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn
Date: Tue, 13 Sep 2016 16:27:05 +1000 [thread overview]
Message-ID: <2042051.3vvUWIM0vs@hex> (raw)
We should not be using smp_processor_id() with preempt enabled.
Bug identified and fix provided by Alfred Chen.
Signed-off-by: Con Kolivas <kernel@kolivas.org>
---
kernel/smpboot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux-4.7.3-ck3/kernel/smpboot.c
===================================================================
--- linux-4.7.3-ck3.orig/kernel/smpboot.c 2016-05-16 08:43:13.000000000 +1000
+++ linux-4.7.3-ck3/kernel/smpboot.c 2016-09-13 16:17:33.535655129 +1000
@@ -122,12 +122,12 @@ static int smpboot_thread_fn(void *data)
if (kthread_should_park()) {
__set_current_state(TASK_RUNNING);
- preempt_enable();
if (ht->park && td->status == HP_THREAD_ACTIVE) {
BUG_ON(td->cpu != smp_processor_id());
ht->park(td->cpu);
td->status = HP_THREAD_PARKED;
}
+ preempt_enable();
kthread_parkme();
/* We might have been woken for stop */
continue;
next reply other threads:[~2016-09-13 6:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-13 6:27 Con Kolivas [this message]
2016-09-22 11:58 ` [tip:sched/core] sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn() tip-bot for Con Kolivas
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