On Fri 06-09-13 11:09:21, Eric W. Biederman wrote: > Michal Hocko <mhocko@xxxxxxx> writes: > > > It seems that this one fell though the cracks? > > Not completely, but it happened just as I was doing my initial triage of > memcg problems and I haven't quite made it back to this. OK. I am primarily asking because I am not sure I understood whether the proposed patch helped or not. It should as per my last email but it is possible that I have missed something... > I have an even nastier memcg hang (without yet an easy reproducer). > During mkdir ext3 can add a page to the page cache with the ext3 journal > transaction lock held. Normally that isn't a problem but freezing there > stops all writes to that filesystem, and the world stops. > > It looks like the only way to avoid that kind of scenario is to move the > the memcg sleep to the edge of userspace, like we do with signals and a > few other things so we can be guaranteed not to increase lock hold > times, when it is avoidable. I think I saw some similar comments about > the slab limiting. Johannes has patches that move memcg oom out of any locks already: https://lkml.org/lkml/2013/8/3/81. There is some development going on there and I guess he will post v3 soon but that sounds it might help with what you describe above. Thanks! -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
