From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id E82976B026C for ; Thu, 11 Jan 2018 09:37:13 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id f64so2219642pfd.6 for ; Thu, 11 Jan 2018 06:37:13 -0800 (PST) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [2001:e42:101:1:202:181:97:72]) by mx.google.com with ESMTPS id l1si2806259pli.690.2018.01.11.06.37.11 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 11 Jan 2018 06:37:12 -0800 (PST) Subject: Re: [mm? 4.15-rc7] Random oopses under memory pressure. From: Tetsuo Handa References: <20180110124519.GU1732@dhcp22.suse.cz> <201801102237.BED34322.QOOJMFFFHVLSOt@I-love.SAKURA.ne.jp> <20180111135721.GC1732@dhcp22.suse.cz> <201801112311.EHI90152.FLJMQOStVHFOFO@I-love.SAKURA.ne.jp> <20180111142148.GD1732@dhcp22.suse.cz> In-Reply-To: <20180111142148.GD1732@dhcp22.suse.cz> Message-Id: <201801112337.HHB95897.JHQOFFtMOOVSFL@I-love.SAKURA.ne.jp> Date: Thu, 11 Jan 2018 23:37:05 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: mhocko@kernel.org Cc: linux-mm@kvack.org, x86@kernel.org, linux-fsdevel@vger.kernel.org Michal Hocko wrote: > On Thu 11-01-18 23:11:12, Tetsuo Handa wrote: > > Michal Hocko wrote: > > > On Wed 10-01-18 22:37:52, Tetsuo Handa wrote: > > > > Michal Hocko wrote: > > > > > On Wed 10-01-18 20:49:56, Tetsuo Handa wrote: > > > > > > Tetsuo Handa wrote: > > > > > > > I can hit this bug with Linux 4.11 and 4.8. (i.e. at least all 4.8+ have this bug.) > > > > > > > So far I haven't hit this bug with Linux 4.8-rc3 and 4.7. > > > > > > > Does anyone know what is happening? > > > > > > > > > > > > I simplified the reproducer and succeeded to reproduce this bug with both > > > > > > i7-2630QM (8 core) and i5-4440S (4 core). Thus, I think that this bug is > > > > > > not architecture specific. > > > > > > > > > > Can you see the same with 64b kernel? > > > > > > > > No. I can hit this bug with only x86_32 kernels. > > > > But if the cause is not specific to 32b, this might be silent memory corruption. > > > > > > > > > It smells like a ref count imbalance and premature page free to me. Can > > > > > you try to bisect this? > > > > > > > > Too difficult to bisect, but at least I can hit this bug with 4.8+ kernels. > > > > The bug in 4.8 kernel might be different from the bug in 4.15-rc7 kernel. > > 4.15-rc7 kernel hits the bug so trivially. > > Maybe you want to disable the oom reaper to reduce chances of some issue > there. I already tried it for 4.15-rc7. The bug can occur before the OOM killer is invoked for the first time after boot. The OOM killer and the OOM reaper are not the culprit. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org