Messages in this thread Patch in this message | | | Date | Thu, 17 Dec 2009 12:31:52 GMT | From | tip-bot for Peter Zijlstra <> | Subject | [tip:sched/urgent] sched: Fix broken assertion |
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Commit-ID: 077614ee1e93245a3b9a4e1213659405dbeb0ba6 Gitweb: http://git.kernel.org/tip/077614ee1e93245a3b9a4e1213659405dbeb0ba6 Author: Peter Zijlstra <a.p.zijlstra@chello.nl> AuthorDate: Thu, 17 Dec 2009 13:16:31 +0100 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Thu, 17 Dec 2009 13:22:46 +0100
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> --- kernel/sched.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c index 7be88a7..720df10 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -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);
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