On Wed, 16 Nov 2011 17:18:09 +0000 Luis Henriques <henrix@xxxxxxxxxxxx> wrote: > On Wed, Nov 16, 2011 at 06:02:42PM +0100, Thomas Gleixner wrote: > > On Wed, 16 Nov 2011, Steven Rostedt wrote: > > > On Wed, 2011-11-16 at 17:16 +0800, Yong Zhang wrote: > > > > Looking at commit 4799401f [memcg: Fix race condition in > > > > memcg_check_events() with this_cpu usage], we just want > > > > to disable migration. So use the right API in -rt. This > > > > will cure below warning. > > > No this won't work. Not even for -rt. If we disable migration but not > > > preemption, then two tasks can take this path. And the checks in > > > __memcg_event_check() will be corrupted because nothing is protecting > > > the updates from two tasks going into the same path. > > > > > > Perhaps a local_lock would work. > > > > Yes, that's the only sensible option for now. Untested patch below. > > I run a quick test and it looks like the problem is gone. > > Cheers, Could you CC the final patch to cgroups@xxxxxxxxxxxxxxx ? Does this fix will go thorugh rt tree rather than -mm ? Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
