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=-11.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 4A369C4727F for ; Wed, 30 Sep 2020 10:48:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F100720789 for ; Wed, 30 Sep 2020 10:48:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="kSGXheRN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729086AbgI3KsY (ORCPT ); Wed, 30 Sep 2020 06:48:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:40846 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725776AbgI3KsV (ORCPT ); Wed, 30 Sep 2020 06:48:21 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1601462900; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7IFfx3OZnBqgehUu2cMHgsqKwAUzAFD3b+C2ju1XQ1M=; b=kSGXheRNDCMV2H2V8U5XRM1cHAIxtJscvMNLblFLwwRrfidDvPGlPhMlrG3r6uyWFZ9oXY YanXrUHiJfGiwjrjUrUcNNMenjR/RUHxXRfHFR1/6VlLiweKCqlQY9y3xFchtwGGU8Aw9I 3+hP1Y9IMTAAk2cLWQSeH7GPviQsPlM= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 340C0ACF5; Wed, 30 Sep 2020 10:48:20 +0000 (UTC) Date: Wed, 30 Sep 2020 12:48:19 +0200 From: Michal Hocko To: Miaohe Lin Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] mm: memcontrol: reword obsolete comment of mem_cgroup_unmark_under_oom() Message-ID: <20200930104819.GS2277@dhcp22.suse.cz> References: <20200930095336.21323-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200930095336.21323-1-linmiaohe@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 30-09-20 05:53:36, Miaohe Lin wrote: > Since commit 79dfdaccd1d5 ("memcg: make oom_lock 0 and 1 based rather than > counter"), the mem_cgroup_unmark_under_oom() is added and the comment of > the mem_cgroup_oom_unlock() is moved here. But this comment make no sense > here because mem_cgroup_oom_lock() does not operate on under_oom field. So > we reword the comment as this would be helpful. > [Thanks Michal Hocko for rewording this comment.] > > Signed-off-by: Miaohe Lin > Cc: Johannes Weiner > Cc: Michal Hocko > Cc: Vladimir Davydov Acked-by: Michal Hocko Thanks! > --- > mm/memcontrol.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 6877c765b8d0..4f0c14cb8690 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1817,8 +1817,8 @@ static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) > struct mem_cgroup *iter; > > /* > - * When a new child is created while the hierarchy is under oom, > - * mem_cgroup_oom_lock() may not be called. Watch for underflow. > + * Be careful about under_oom underflows becase a child memcg > + * could have been added after mem_cgroup_mark_under_oom. > */ > spin_lock(&memcg_oom_lock); > for_each_mem_cgroup_tree(iter, memcg) > -- > 2.19.1 -- Michal Hocko SUSE Labs