From: Peter Zijlstra commit 077614ee1e93245a3b9a4e1213659405dbeb0ba6 upstream 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 LKML-Reference: <20091217121830.137155561@chello.nl> Signed-off-by: Ingo Molnar Signed-off-by: Mike Galbraith Signed-off-by: Greg Kroah-Hartman --- kernel/sched.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2071,7 +2071,8 @@ void set_task_cpu(struct task_struct *p, * 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/