From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-f176.google.com (mail-yk0-f176.google.com [209.85.160.176]) by kanga.kvack.org (Postfix) with ESMTP id F13916B0253 for ; Wed, 20 Jan 2016 10:10:45 -0500 (EST) Received: by mail-yk0-f176.google.com with SMTP id v14so12564318ykd.3 for ; Wed, 20 Jan 2016 07:10:45 -0800 (PST) Received: from mail-yk0-x233.google.com (mail-yk0-x233.google.com. [2607:f8b0:4002:c07::233]) by mx.google.com with ESMTPS id d188si8720976ybc.115.2016.01.20.07.10.45 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Jan 2016 07:10:45 -0800 (PST) Received: by mail-yk0-x233.google.com with SMTP id k129so12664933yke.0 for ; Wed, 20 Jan 2016 07:10:45 -0800 (PST) Date: Wed, 20 Jan 2016 10:10:44 -0500 From: Tejun Heo Subject: Re: [BUG] oom hangs the system, NMI backtrace shows most CPUs in shrink_slab Message-ID: <20160120151044.GA5157@mtj.duckdns.org> References: <569D06F8.4040209@redhat.com> <569E1010.2070806@I-love.SAKURA.ne.jp> <569E5287.4080503@redhat.com> <201601201923.DCC48978.FSHLOQtOVJFFOM@I-love.SAKURA.ne.jp> <201601202217.BEF43262.QOLFHOOJFVFtMS@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201601202217.BEF43262.QOLFHOOJFVFtMS@I-love.SAKURA.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: jiangshanlai@gmail.com, jstancek@redhat.com, linux-mm@kvack.org, ltp@lists.linux.it On Wed, Jan 20, 2016 at 10:17:23PM +0900, Tetsuo Handa wrote: > What happens if memory allocation requests from items using this workqueue > got stuck due to OOM livelock? Are pending items in this workqueue cannot > be processed because this workqueue was created without WQ_MEM_RECLAIM? If something gets stuck due to OOM livelock, anything which tries to allocate memory can hang. That's why it's called a livelock. WQ_MEM_RECLAIM or not wouldn't make any difference. > I don't know whether accessing swap memory depends on this workqueue. > But if disk driver depends on this workqueue for accessing swap partition > on the disk, some event is looping inside memory allocator will result in > unable to process disk I/O request for accessing swap partition on the disk? What you're saying is too vauge for me to decipher exactly what you have on mind. Can you please elaborate? -- tejun -- 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