From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Lameter Subject: Re: [v7 5/5] mm, oom: cgroup v2 mount option to disable cgroup-aware OOM killer Date: Thu, 7 Sep 2017 12:03:08 -0500 (CDT) Message-ID: References: <20170905134412.qdvqcfhvbdzmarna@dhcp22.suse.cz> <20170905143021.GA28599@castle.dhcp.TheFacebook.com> <20170905151251.luh4wogjd3msfqgf@dhcp22.suse.cz> <20170905191609.GA19687@castle.dhcp.TheFacebook.com> <20170906084242.l4rcx6n3hdzxvil6@dhcp22.suse.cz> <20170906174043.GA12579@castle.DHCP.thefacebook.com> <20170907145239.GA19022@castle.DHCP.thefacebook.com> <20170907164245.GA21177@castle.DHCP.thefacebook.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: <20170907164245.GA21177@castle.DHCP.thefacebook.com> Sender: linux-doc-owner@vger.kernel.org To: Roman Gushchin Cc: David Rientjes , nzimmer@sgi.com, holt@sgi.com, Michal Hocko , linux-mm@kvack.org, Vladimir Davydov , Johannes Weiner , Tetsuo Handa , Andrew Morton , Tejun Heo , kernel-team@fb.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, sivanich@sgi.com List-Id: linux-mm.kvack.org On Thu, 7 Sep 2017, Roman Gushchin wrote: > On Thu, Sep 07, 2017 at 10:03:24AM -0500, Christopher Lameter wrote: > > On Thu, 7 Sep 2017, Roman Gushchin wrote: > > > > > > Really? From what I know and worked on way back when: The reason was to be > > > > able to contain the affected application in a cpuset. Multiple apps may > > > > have been running in multiple cpusets on a large NUMA machine and the OOM > > > > condition in one cpuset should not affect the other. It also helped to > > > > isolate the application behavior causing the oom in numerous cases. > > > > > > > > Doesnt this requirement transfer to cgroups in the same way? > > > > > > We have per-node memory stats and plan to use them during the OOM victim > > > selection. Hopefully it can help. > > > > One of the OOM causes could be that memory was restricted to a certain > > node set. Killing the allocating task is (was?) default behavior in that > > case so that the task that has the restrictions is killed. Not any task > > that may not have the restrictions and woiuld not experience OOM. > > As I can see, it's not the default behavior these days. If we have a way > to select a victim between memcgs/tasks which are actually using > the corresponding type of memory, it's much better than to kill > an allocating task. Kill the whole set of processes constituting an app in a cgroup or so sounds good to me.