From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39199C433E1 for ; Thu, 20 Aug 2020 16:26:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 224AC207BB for ; Thu, 20 Aug 2020 16:26:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729474AbgHTQ0t (ORCPT ); Thu, 20 Aug 2020 12:26:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:50180 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727780AbgHTQ0t (ORCPT ); Thu, 20 Aug 2020 12:26:49 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 27CCBAD56; Thu, 20 Aug 2020 16:27:14 +0000 (UTC) Date: Thu, 20 Aug 2020 18:26:45 +0200 From: Michal Hocko To: Suren Baghdasaryan Cc: "Eric W. Biederman" , Tetsuo Handa , Christian Brauner , Tim Murray , mingo@kernel.org, Peter Zijlstra , Thomas Gleixner , esyr@redhat.com, christian@kellner.me, areber@redhat.com, Shakeel Butt , cyphar@cyphar.com, Oleg Nesterov , adobriyan@gmail.com, Andrew Morton , gladkov.alexey@gmail.com, Michel Lespinasse , daniel.m.jordan@oracle.com, avagin@gmail.com, bernd.edlinger@hotmail.de, John Johansen , laoar.shao@gmail.com, Minchan Kim , kernel-team , LKML , linux-fsdevel@vger.kernel.org, linux-mm Subject: Re: [PATCH 1/1] mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary Message-ID: <20200820162645.GP5033@dhcp22.suse.cz> References: <20200820124241.GJ5033@dhcp22.suse.cz> <87lfi9xz7y.fsf@x220.int.ebiederm.org> <87d03lxysr.fsf@x220.int.ebiederm.org> <20200820132631.GK5033@dhcp22.suse.cz> <20200820133454.ch24kewh42ax4ebl@wittgenstein> <20200820140054.fdkbotd4tgfrqpe6@wittgenstein> <637ab0e7-e686-0c94-753b-b97d24bb8232@i-love.sakura.ne.jp> <87k0xtv0d4.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu 20-08-20 08:56:53, Suren Baghdasaryan wrote: [...] > Catching up on the discussion which was going on while I was asleep... > So it sounds like there is a consensus that oom_adj should be moved to > mm_struct rather than trying to synchronize it among tasks sharing mm. > That sounds reasonable to me too. Michal answered all the earlier > questions about this patch, so I won't be reiterating them, thanks > Michal. If any questions are still lingering about the original patch > I'll be glad to answer them. I think it still makes some sense to go with a simpler (aka less tricky) solution which would be your original patch with an incremental fix for vfork and the proper ordering (http://lkml.kernel.org/r/20200820124109.GI5033@dhcp22.suse.cz) and then make a more complex shift to mm struct on top of that. The former will be less tricky to backport to stable IMHO. -- Michal Hocko SUSE Labs