Messages in this thread | | | Date | Wed, 17 Feb 2010 09:01:24 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [patch -mm 4/9 v2] oom: remove compulsory panic_on_oom mode |
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On Tue, 16 Feb 2010 15:54:50 -0800 (PST) David Rientjes <rientjes@google.com> wrote:
> On Wed, 17 Feb 2010, KAMEZAWA Hiroyuki wrote: > > Then, please leave panic_on_oom=always. > > Even with mempolicy or cpuset 's OOM, we need panic_on_oom=always option. > > And yes, I'll add something similar to memcg. freeze_at_oom or something. > > > > Memcg isn't a special case here, it should also panic the machine if > panic_on_oom == 2, so if we aren't going to remove this option then I > agree with Nick that we need to panic from mem_cgroup_out_of_memory() as > well. Some users use cpusets, for example, for the same effect of memory > isolation as you use memcg, so panicking in one scenario and not the other > is inconsistent. > Hmm, I have a few reason to add special behavior to memcg rather than panic.
- freeze_at_oom is enough. If OOM can be notified, the management daemon can do useful jobs. Shutdown all other cgroups or migrate them to other host and do kdump.
- memcg's oom is not very complicated. Because we just counts RSS+FileCache
But, Hmm...I'd like to go this way.
1. At first, support panic_on_oom=2 in memcg.
2. Second, I'll add OOM-notifier and freeze_at_oom to memcg. and don't call memcg_out_of_memory in oom_kill.c in this case. Because we don't kill anything. Taking coredumps of all procs in memcg is not very difficult.
I need to discuss with memcg guys. But this will be a way to go, I think
Thanks, -Kame
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