From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) by kanga.kvack.org (Postfix) with ESMTP id CDEA28E0001 for ; Thu, 10 Jan 2019 19:23:51 -0500 (EST) Received: by mail-pl1-f198.google.com with SMTP id x7so7170633pll.23 for ; Thu, 10 Jan 2019 16:23:51 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id d16si201256pfn.169.2019.01.10.16.23.50 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Jan 2019 16:23:50 -0800 (PST) Subject: Re: [kbuild-all] [PATCH 2/2] memcg: do not report racy no-eligible OOM tasks References: <20190107143802.16847-3-mhocko@kernel.org> <201901081642.Q6tXklr0%fengguang.wu@intel.com> <20190108093959.GQ31793@dhcp22.suse.cz> From: Rong Chen Message-ID: Date: Fri, 11 Jan 2019 08:23:57 +0800 MIME-Version: 1.0 In-Reply-To: <20190108093959.GQ31793@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko , kbuild test robot Cc: Tetsuo Handa , LKML , linux-mm@kvack.org, kbuild-all@01.org, Johannes Weiner , Andrew Morton On 01/08/2019 05:39 PM, Michal Hocko wrote: > On Tue 08-01-19 16:35:42, kbuild test robot wrote: > [...] >> All warnings (new ones prefixed by >>): >> >> include/linux/rcupdate.h:659:9: warning: context imbalance in 'find_lock_task_mm' - wrong count at exit >> include/linux/sched/mm.h:141:37: warning: dereference of noderef expression >> mm/oom_kill.c:225:28: warning: context imbalance in 'oom_badness' - unexpected unlock >> mm/oom_kill.c:406:9: warning: context imbalance in 'dump_tasks' - different lock contexts for basic block >>>> mm/oom_kill.c:918:17: warning: context imbalance in '__oom_kill_process' - unexpected unlock > What exactly does this warning say? I do not see anything wrong about > the code. find_lock_task_mm returns a locked task when t != NULL and > mark_oom_victim doesn't do anything about the locking. Am I missing > something or the warning is just confused? Thanks for your reply. It looks like a false positive. We'll look into it. Best Regards, Rong Chen > > [...] >> 00508538 Michal Hocko 2019-01-07 915 t = find_lock_task_mm(p); >> 00508538 Michal Hocko 2019-01-07 916 if (!t) >> 00508538 Michal Hocko 2019-01-07 917 continue; >> 00508538 Michal Hocko 2019-01-07 @918 mark_oom_victim(t); >> 00508538 Michal Hocko 2019-01-07 919 task_unlock(t); >> 647f2bdf David Rientjes 2012-03-21 920 }