2.6.37-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Peter Zijlstra <[email protected]>

commit 06c3bc655697b19521901f9254eb0bbb2c67e7e8 upstream.

cpu_stopper_thread()
  migration_cpu_stop()
    __migrate_task()
      deactivate_task()
        dequeue_task()
          dequeue_task_rq()
            update_curr_rt()

Will call update_curr_rt() on rq->curr, which at that time is
rq->stop. The problem is that rq->stop.prio matches an RT prio and
thus falsely assumes its a rt_sched_class task.

Reported-Debuged-Tested-Acked-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 kernel/sched_rt.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -606,7 +606,7 @@ static void update_curr_rt(struct rq *rq
        struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
        u64 delta_exec;
 
-       if (!task_has_rt_policy(curr))
+       if (curr->sched_class != &rt_sched_class)
                return;
 
        delta_exec = rq->clock_task - curr->se.exec_start;


_______________________________________________
stable mailing list
[email protected]
http://linux.kernel.org/mailman/listinfo/stable

Reply via email to