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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 65D71C04AB4 for ; Mon, 13 May 2019 08:51:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2AEAB21479 for ; Mon, 13 May 2019 08:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557737478; bh=z64fTty09J+ze652b8Ro4nMYClhF2toa+sANVIPy/Uc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Cqlqd/ua19tOday1L6Efcg209uc1ezJKzo7y8EeL5Y9Gw/fXM3x6WAYo2Su1R08A4 gsACAspeRquRaQdeV7AKpCiXR8ZKozG3brWHRvyUiKq0x4usdNPXVjMw3KolEV+24Q ipF6JUgPNMgVlSWW0LzSzD69B5xpVajsZJzQnrVM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728353AbfEMIvQ (ORCPT ); Mon, 13 May 2019 04:51:16 -0400 Received: from mx2.suse.de ([195.135.220.15]:52442 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727967AbfEMIvQ (ORCPT ); Mon, 13 May 2019 04:51:16 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 12230AECD; Mon, 13 May 2019 08:51:15 +0000 (UTC) Date: Mon, 13 May 2019 10:51:14 +0200 From: Michal Hocko To: Shakeel Butt Cc: Johannes Weiner , Vladimir Davydov , Andrew Morton , Roman Gushchin , Jan Kara , Amir Goldstein , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [RESEND PATCH v2 2/2] memcg, fsnotify: no oom-kill for remote memcg charging Message-ID: <20190513085114.GD24036@dhcp22.suse.cz> References: <20190512160927.80042-1-shakeelb@google.com> <20190512160927.80042-2-shakeelb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190512160927.80042-2-shakeelb@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun 12-05-19 09:09:27, Shakeel Butt wrote: [...] > diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c > index 6b9c27548997..f78fd4c8f12d 100644 > --- a/fs/notify/fanotify/fanotify.c > +++ b/fs/notify/fanotify/fanotify.c > @@ -288,10 +288,13 @@ struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group, > /* > * For queues with unlimited length lost events are not expected and > * can possibly have security implications. Avoid losing events when > - * memory is short. > + * memory is short. Also make sure to not trigger OOM killer in the > + * target memcg for the limited size queues. > */ > if (group->max_events == UINT_MAX) > gfp |= __GFP_NOFAIL; > + else > + gfp |= __GFP_RETRY_MAYFAIL; > > /* Whoever is interested in the event, pays for the allocation. */ > memalloc_use_memcg(group->memcg); > diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c > index ff30abd6a49b..17c08daa1ba7 100644 > --- a/fs/notify/inotify/inotify_fsnotify.c > +++ b/fs/notify/inotify/inotify_fsnotify.c > @@ -99,9 +99,12 @@ int inotify_handle_event(struct fsnotify_group *group, > i_mark = container_of(inode_mark, struct inotify_inode_mark, > fsn_mark); > > - /* Whoever is interested in the event, pays for the allocation. */ > + /* > + * Whoever is interested in the event, pays for the allocation. However > + * do not trigger the OOM killer in the target memcg. Both comments would be much more helpful if they mentioned _why_ we do not want to trigger the OOM iller. > + */ > memalloc_use_memcg(group->memcg); > - event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT); > + event = kmalloc(alloc_len, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL); > memalloc_unuse_memcg(); > > if (unlikely(!event)) { -- Michal Hocko SUSE Labs