Commit 077614ee authored Dec 17, 2009 by Peter Zijlstra Committed by Ingo Molnar Dec 17, 2009

sched: Fix broken assertion



There's a preemption race in the set_task_cpu() debug check in
that when we get preempted after setting task->state we'd still
be on the rq proper, but fail the test.

Check for preempted tasks, since those are always on the RQ.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121830.137155561@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent e1781538

kernel/sched.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2041,7 +2041,8 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
		* We should never call set_task_cpu() on a blocked task,
		* ttwu() will sort out the placement.
		*/
		WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING);
		WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
		!(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
		#endif

		trace_sched_migrate_task(p, new_cpu);