timers: split process wide cpu clocks/timers, remove spurious warning

Mike Galbraith reported that the new warning in thread_group_cputimer()
triggers en masse with Amarok running.

Oleg Nesterov observed:

  Can't fastpath_timer_check()->thread_group_cputimer() have the
  false warning too? Suppose we had the timer, then posix_cpu_timer_del()
  removes this timer, but task_cputime_zero(&sig->cputime_expires) still
  not true.

Remove the spurious debug warning.

Reported-by: Mike Galbraith <efault@gmx.de>
Explained-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 082d7619b3a1e0ecc456828ba58a518028595fb6..79392916d6c97fb5583982eb2bf1a92a6e06997e 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2208,8 +2208,6 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
        struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
        unsigned long flags;
 
-       WARN_ON(!cputimer->running);
-
        spin_lock_irqsave(&cputimer->lock, flags);
        *times = cputimer->cputime;
        spin_unlock_irqrestore(&cputimer->lock, flags);