From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id A23F56B0038 for ; Fri, 1 Dec 2017 03:41:17 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id a13so6083040pgt.0 for ; Fri, 01 Dec 2017 00:41:17 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id 76si4817170pfi.64.2017.12.01.00.41.16 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 01 Dec 2017 00:41:16 -0800 (PST) Date: Fri, 1 Dec 2017 09:41:13 +0100 From: Michal Hocko Subject: Re: [PATCH v13 5/7] mm, oom: add cgroup v2 mount option for cgroup-aware OOM killer Message-ID: <20171201084113.47lnuo3diwxts732@dhcp22.suse.cz> References: <20171130152824.1591-1-guro@fb.com> <20171130152824.1591-6-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171130152824.1591-6-guro@fb.com> Sender: owner-linux-mm@kvack.org List-ID: To: Roman Gushchin Cc: linux-mm@vger.kernel.org, Vladimir Davydov , Johannes Weiner , Tetsuo Handa , David Rientjes , Andrew Morton , Tejun Heo , kernel-team@fb.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org On Thu 30-11-17 15:28:22, Roman Gushchin wrote: > Add a "groupoom" cgroup v2 mount option to enable the cgroup-aware > OOM killer. If not set, the OOM selection is performed in > a "traditional" per-process way. > > The behavior can be changed dynamically by remounting the cgroupfs. Is it ok to create oom_group if the option is not enabled? This looks confusing. I forgot all the details about how cgroup core creates file so I do not have a good idea how to fix this. > Signed-off-by: Roman Gushchin > Cc: Michal Hocko > Cc: Vladimir Davydov > Cc: Johannes Weiner > Cc: Tetsuo Handa > Cc: David Rientjes > Cc: Andrew Morton > Cc: Tejun Heo > Cc: kernel-team@fb.com > Cc: cgroups@vger.kernel.org > Cc: linux-doc@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: linux-mm@kvack.org > --- > include/linux/cgroup-defs.h | 5 +++++ > kernel/cgroup/cgroup.c | 10 ++++++++++ > mm/memcontrol.c | 3 +++ > 3 files changed, 18 insertions(+) > > diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h > index 8b7fd8eeccee..9fb99e25d654 100644 > --- a/include/linux/cgroup-defs.h > +++ b/include/linux/cgroup-defs.h > @@ -81,6 +81,11 @@ enum { > * Enable cpuset controller in v1 cgroup to use v2 behavior. > */ > CGRP_ROOT_CPUSET_V2_MODE = (1 << 4), > + > + /* > + * Enable cgroup-aware OOM killer. > + */ > + CGRP_GROUP_OOM = (1 << 5), > }; > > /* cftype->flags */ > diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c > index 0b1ffe147f24..7338e12979e1 100644 > --- a/kernel/cgroup/cgroup.c > +++ b/kernel/cgroup/cgroup.c > @@ -1731,6 +1731,9 @@ static int parse_cgroup_root_flags(char *data, unsigned int *root_flags) > if (!strcmp(token, "nsdelegate")) { > *root_flags |= CGRP_ROOT_NS_DELEGATE; > continue; > + } else if (!strcmp(token, "groupoom")) { > + *root_flags |= CGRP_GROUP_OOM; > + continue; > } > > pr_err("cgroup2: unknown option \"%s\"\n", token); > @@ -1747,6 +1750,11 @@ static void apply_cgroup_root_flags(unsigned int root_flags) > cgrp_dfl_root.flags |= CGRP_ROOT_NS_DELEGATE; > else > cgrp_dfl_root.flags &= ~CGRP_ROOT_NS_DELEGATE; > + > + if (root_flags & CGRP_GROUP_OOM) > + cgrp_dfl_root.flags |= CGRP_GROUP_OOM; > + else > + cgrp_dfl_root.flags &= ~CGRP_GROUP_OOM; > } > } > > @@ -1754,6 +1762,8 @@ static int cgroup_show_options(struct seq_file *seq, struct kernfs_root *kf_root > { > if (cgrp_dfl_root.flags & CGRP_ROOT_NS_DELEGATE) > seq_puts(seq, ",nsdelegate"); > + if (cgrp_dfl_root.flags & CGRP_GROUP_OOM) > + seq_puts(seq, ",groupoom"); > return 0; > } > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 5d27a4bbd478..c76d5fb55c5c 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2869,6 +2869,9 @@ bool mem_cgroup_select_oom_victim(struct oom_control *oc) > if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) > return false; > > + if (!(cgrp_dfl_root.flags & CGRP_GROUP_OOM)) > + return false; > + > if (oc->memcg) > root = oc->memcg; > else > -- > 2.14.3 -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org