From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757929Ab2JLJrc (ORCPT ); Fri, 12 Oct 2012 05:47:32 -0400 Received: from cantor2.suse.de ([195.135.220.15]:37482 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757855Ab2JLJra (ORCPT ); Fri, 12 Oct 2012 05:47:30 -0400 Date: Fri, 12 Oct 2012 11:47:26 +0200 From: Michal Hocko To: Glauber Costa Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Mel Gorman , Suleiman Souhlal , Tejun Heo , cgroups@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, Johannes Weiner , Greg Thelen , devel@openvz.org, Frederic Weisbecker , Christoph Lameter , Pekka Enberg Subject: Re: [PATCH v4 06/14] memcg: kmem controller infrastructure Message-ID: <20121012094726.GH10110@dhcp22.suse.cz> References: <1349690780-15988-1-git-send-email-glommer@parallels.com> <1349690780-15988-7-git-send-email-glommer@parallels.com> <20121011124212.GC29295@dhcp22.suse.cz> <5077CAAA.3090709@parallels.com> <20121012083944.GD10110@dhcp22.suse.cz> <5077D889.2040100@parallels.com> <20121012085740.GG10110@dhcp22.suse.cz> <5077DF20.7020200@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5077DF20.7020200@parallels.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 12-10-12 13:13:04, Glauber Costa wrote: [...] > Just so we don't ping-pong in another submission: > > I changed memcontrol.h's memcg_kmem_newpage_charge to include: > > /* If the test is dying, just let it go. */ > if (unlikely(test_thread_flag(TIF_MEMDIE) > || fatal_signal_pending(current))) > return true; OK > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index c32aaaf..72cf189 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > +static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size) > +{ > + struct res_counter *fail_res; > + struct mem_cgroup *_memcg; > + int ret = 0; > + bool may_oom; > + > + ret = res_counter_charge(&memcg->kmem, size, &fail_res); > + if (ret) > + return ret; > + > + /* > + * Conditions under which we can wait for the oom_killer. > + * We have to be able to wait, but also, if we can't retry, > + * we obviously shouldn't go mess with oom. > + */ > + may_oom = (gfp & __GFP_WAIT) && !(gfp & __GFP_NORETRY); > + > + _memcg = memcg; > + ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT, > + &_memcg, may_oom); > + > + if (ret == -EINTR) { > + /* > + * __mem_cgroup_try_charge() chosed to bypass to root due to > + * OOM kill or fatal signal. Since our only options are to > + * either fail the allocation or charge it to this cgroup, do > + * it as a temporary condition. But we can't fail. From a > + * kmem/slab perspective, the cache has already been selected, > + * by mem_cgroup_get_kmem_cache(), so it is too late to change > + * our minds. This condition will only trigger if the task > + * entered memcg_charge_kmem in a sane state, but was > + * OOM-killed. during __mem_cgroup_try_charge. Tasks that are > + * already dying when the allocation triggers should have been > + * already directed to the root cgroup. > + */ > + res_counter_charge_nofail(&memcg->res, size, &fail_res); > + if (do_swap_account) > + res_counter_charge_nofail(&memcg->memsw, size, > + &fail_res); > + ret = 0; > + } else if (ret) > + res_counter_uncharge(&memcg->kmem, size); > + > + return ret; > +} OK -- Michal Hocko SUSE Labs