From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend Date: Wed, 5 Nov 2014 12:01:11 -0500 Message-ID: <20141105170111.GG14386@htj.dyndns.org> References: <20141104192705.GA22163@htj.dyndns.org> <20141105124620.GB4527@dhcp22.suse.cz> <20141105130247.GA14386@htj.dyndns.org> <20141105133100.GC4527@dhcp22.suse.cz> <20141105134219.GD4527@dhcp22.suse.cz> <20141105154436.GB14386@htj.dyndns.org> <20141105160115.GA28226@dhcp22.suse.cz> <20141105162929.GD14386@htj.dyndns.org> <20141105163956.GD28226@dhcp22.suse.cz> <20141105165428.GF14386@htj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20141105165428.GF14386@htj.dyndns.org> Sender: owner-linux-mm@kvack.org To: Michal Hocko Cc: "Rafael J. Wysocki" , Andrew Morton , Cong Wang , David Rientjes , Oleg Nesterov , LKML , linux-mm@kvack.org, Linux PM list List-Id: linux-pm@vger.kernel.org On Wed, Nov 05, 2014 at 11:54:28AM -0500, Tejun Heo wrote: > > Still not following. How do you want to detect an on-going OOM without > > any interface around out_of_memory? > > I thought you were using oom_killer_allowed_start() outside OOM path. > Ugh.... why is everything weirdly structured? oom_killer_disabled > implies that oom killer may fail, right? Why is > __alloc_pages_slowpath() checking it directly? If whether oom killing > failed or not is relevant to its users, make out_of_memory() return an > error code. There's no reason for the exclusion detail to leak out of > the oom killer proper. The only interface should be disable/enable > and whether oom killing failed or not. And what's implemented is wrong. What happens if oom killing is already in progress and then a task blocks trying to write-lock the rwsem and then that task is selected as the OOM victim? disable() call must be able to fail. -- tejun -- 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