sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn()

We should not be using smp_processor_id() with preempt enabled.

Bug identified and fix provided by Alfred Chen.

Reported-by: Alfred Chen <cchalpha@gmail.com>
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Alfred Chen <cchalpha@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/2042051.3vvUWIM0vs@hex
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Con Kolivas 2016-09-13 16:27:05 +10:00 committed by Ingo Molnar
parent d59dc7bcfa
commit 4fa5cd5245

View file

@ -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;