On Tue, 23 Sep 2014 16:20:37 +0200 Peter Zijlstra <[email protected]> wrote:
> On Tue, Sep 23, 2014 at 07:45:22AM -0400, Rik van Riel wrote: > > > > I really thing the preempt_disable/enable is not needed. > > > > > > Paul, Thomas, care to comment? > > > > I suspect you are right. On normal kernels, rcu_read_lock() will > > ensure preemption is disabled. > > > > On -rt, the locks within are all sleepable mutexes. > > > > Either way, things should be ok. > > But with CONFIG_PREEMPT we get preemptible RCU but not the > spinlock->rt_mutex conversion. Right, I was about to say that. That is, rcu_read_lock() in mainline does not always disable preemption (See CONFIG_PREEMPT_RCU). But I still think this should be safe. I don't see the siglock ever being taking in the scheduler or by rt_mutex_unlock(). -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
