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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7A6D3C43444 for ; Tue, 8 Jan 2019 09:40:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4910A20827 for ; Tue, 8 Jan 2019 09:40:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546940403; bh=PHIUOyU8EM08ZnzmNoelTGGz+oCrDFD66qWgPeWFyAc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=tQU+fvjg0d8NUNlf4z7958hCuUHZ1F57FZN7k6C9u7IacF96g8XgYRJCOj9Pxqap6 q9B2LYZ1w5kPLpIxULX9YuZfE7JKnAMAgxgDGwmbKcuSMpRg90HpP9WQKYgxLwfFFP sIUxnZgnrNOJIxPHfu5GajkzLQFwiyJszy5JXasM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727867AbfAHJkB (ORCPT ); Tue, 8 Jan 2019 04:40:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:54528 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727001AbfAHJkB (ORCPT ); Tue, 8 Jan 2019 04:40:01 -0500 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 1F692ABE4; Tue, 8 Jan 2019 09:40:00 +0000 (UTC) Date: Tue, 8 Jan 2019 10:39:59 +0100 From: Michal Hocko To: kbuild test robot Cc: kbuild-all@01.org, linux-mm@kvack.org, Tetsuo Handa , Johannes Weiner , Andrew Morton , LKML Subject: Re: [PATCH 2/2] memcg: do not report racy no-eligible OOM tasks Message-ID: <20190108093959.GQ31793@dhcp22.suse.cz> References: <20190107143802.16847-3-mhocko@kernel.org> <201901081642.Q6tXklr0%fengguang.wu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201901081642.Q6tXklr0%fengguang.wu@intel.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 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? [...] > 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 } -- Michal Hocko SUSE Labs