From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id 926096B0003 for ; Mon, 6 Aug 2018 15:46:00 -0400 (EDT) Received: by mail-pl0-f72.google.com with SMTP id n21-v6so9126134plp.9 for ; Mon, 06 Aug 2018 12:46:00 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id b59-v6si10810376plc.11.2018.08.06.12.45.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Aug 2018 12:45:58 -0700 (PDT) Date: Mon, 6 Aug 2018 21:45:53 +0200 From: Michal Hocko Subject: Re: WARNING in try_charge Message-ID: <20180806194553.GH10003@dhcp22.suse.cz> References: <20180806185554.GG10003@dhcp22.suse.cz> <0000000000006986c30572c90de3@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0000000000006986c30572c90de3@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: syzbot Cc: cgroups@vger.kernel.org, dvyukov@google.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, penguin-kernel@I-love.SAKURA.ne.jp, syzkaller-bugs@googlegroups.com, vdavydov.dev@gmail.com [CCing Greg - the email thread starts here http://lkml.kernel.org/r/0000000000005e979605729c1564@google.com] On Mon 06-08-18 12:12:02, syzbot wrote: > Hello, > > syzbot has tested the proposed patch and the reproducer did not trigger > crash: OK, this is reassuring. Btw Greg has pointed out this potential case http://lkml.kernel.org/r/xr93in62jy8k.fsf@gthelen.svl.corp.google.com but I simply didn't get what he meant. He was suggesting MMF_OOM_SKIP but I didn't get why that matters. I didn't think about a race. So how about this patch: