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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E6D7CC433DF for ; Thu, 2 Jul 2020 08:17:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC51C20772 for ; Thu, 2 Jul 2020 08:17:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726435AbgGBIRg (ORCPT ); Thu, 2 Jul 2020 04:17:36 -0400 Received: from proxmox-new.maurer-it.com ([212.186.127.180]:59973 "EHLO proxmox-new.maurer-it.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726042AbgGBIRg (ORCPT ); Thu, 2 Jul 2020 04:17:36 -0400 X-Greylist: delayed 314 seconds by postgrey-1.27 at vger.kernel.org; Thu, 02 Jul 2020 04:17:35 EDT Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 9D6EC42F88; Thu, 2 Jul 2020 10:12:20 +0200 (CEST) Subject: Re: [Patch net] cgroup: fix cgroup_sk_alloc() for sk_clone_lock() To: Cong Wang , Roman Gushchin Cc: Cameron Berkenpas , Zefan Li , Linux Kernel Network Developers , Peter Geis , Lu Fengqi , =?UTF-8?Q?Dani=c3=abl_Sonck?= , Daniel Borkmann , Tejun Heo References: <4f17229e-1843-5bfc-ea2f-67ebaa9056da@huawei.com> <459be87d-0272-9ea9-839a-823b01e354b6@huawei.com> <35480172-c77e-fb67-7559-04576f375ea6@huawei.com> <20200623222137.GA358561@carbon.lan> <20200627234127.GA36944@carbon.DHCP.thefacebook.com> <20200630224829.GC37586@carbon.dhcp.thefacebook.com> From: Thomas Lamprecht Message-ID: Date: Thu, 2 Jul 2020 10:12:19 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 02.07.20 06:48, Cong Wang wrote: > On Tue, Jun 30, 2020 at 3:48 PM Roman Gushchin wrote: >> >> Btw if we want to backport the problem but can't blame a specific commit, >> we can always use something like "Cc: [3.1+]". > > Sure, but if we don't know which is the right commit to blame, then how > do we know which stable version should the patch target? :) We run into a similar issue here once we made an update from the 5.4.41 to the 5.4.44 stable kernel. This patch addresses the issue, at least we are running stable at >17 hours uptime with this patch, whereas we ran into issues normally at <6 hour uptime without this patch. That update included newly the commit 090e28b229af92dc5b ("netprio_cgroup: Fix unlimited memory leak of v2 cgroups") which this patch originally mentions as "Fixes", whereas the other mentioned possible culprit 4bfc0bb2c60e2f4c ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself") was included with 5.2 here, and did *not* made problems here. So, while the real culprit may be something else, a mix of them, or even more complex, the race is at least triggered way more frequently with the 090e28b229af92dc5b ("netprio_cgroup: Fix unlimited memory leak of v2 cgroups") one or, for the sake of mentioning, possibly also something else from the v5.4.41..v5.4.44 commit range - I did not looked into that in detail yet. > > I am open to all options here, including not backporting to stable at all. As said, the stable-5.4.y tree profits from having this patch here, so there's that. Also, FWIW: Tested-by: Thomas Lamprecht