From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) by kanga.kvack.org (Postfix) with ESMTP id 8BF026B0008 for ; Sat, 13 Oct 2018 07:29:08 -0400 (EDT) Received: by mail-oi1-f197.google.com with SMTP id f62-v6so10048894oia.2 for ; Sat, 13 Oct 2018 04:29:08 -0700 (PDT) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [202.181.97.72]) by mx.google.com with ESMTPS id h67si1947959otb.45.2018.10.13.04.29.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 13 Oct 2018 04:29:07 -0700 (PDT) Subject: Re: [RFC PATCH] memcg, oom: throttle dump_header for memcg ooms without eligible tasks References: <000000000000dc48d40577d4a587@google.com> <20181010151135.25766-1-mhocko@kernel.org> <20181012112008.GA27955@cmpxchg.org> <20181012120858.GX5873@dhcp22.suse.cz> <9174f087-3f6f-f0ed-6009-509d4436a47a@i-love.sakura.ne.jp> <20181012124137.GA29330@cmpxchg.org> <0417c888-d74e-b6ae-a8f0-234cbde03d38@i-love.sakura.ne.jp> <20181013112238.GA762@cmpxchg.org> From: Tetsuo Handa Message-ID: Date: Sat, 13 Oct 2018 20:28:38 +0900 MIME-Version: 1.0 In-Reply-To: <20181013112238.GA762@cmpxchg.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Michal Hocko Cc: linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, guro@fb.com, kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org, rientjes@google.com, yang.s@alibaba-inc.com, Andrew Morton , Sergey Senozhatsky , Petr Mladek , Sergey Senozhatsky , Steven Rostedt On 2018/10/13 20:22, Johannes Weiner wrote: > On Sat, Oct 13, 2018 at 08:09:30PM +0900, Tetsuo Handa wrote: >> ---------- Michal's patch ---------- >> >> 73133 lines (5.79MB) of kernel messages per one run >> >> [root@ccsecurity ~]# time ./a.out >> >> real 3m44.389s >> user 0m0.000s >> sys 3m42.334s >> >> [root@ccsecurity ~]# time ./a.out >> >> real 3m41.767s >> user 0m0.004s >> sys 3m39.779s >> >> ---------- My v2 patch ---------- >> >> 50 lines (3.40 KB) of kernel messages per one run >> >> [root@ccsecurity ~]# time ./a.out >> >> real 0m5.227s >> user 0m0.000s >> sys 0m4.950s >> >> [root@ccsecurity ~]# time ./a.out >> >> real 0m5.249s >> user 0m0.000s >> sys 0m4.956s > > Your patch is suppressing information that I want to have and my > console can handle, just because your console is slow, even though > there is no need to use that console at that log level. My patch is not suppressing information you want to have. My patch is mainly suppressing [ 52.393146] Out of memory and no killable processes... [ 52.395195] a.out invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=-1000 [ 52.398623] Out of memory and no killable processes... [ 52.401195] a.out invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=-1000 [ 52.404356] Out of memory and no killable processes... [ 52.406492] a.out invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=-1000 [ 52.409595] Out of memory and no killable processes... [ 52.411745] a.out invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=-1000 [ 52.415588] Out of memory and no killable processes... [ 52.418484] a.out invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=-1000 [ 52.421904] Out of memory and no killable processes... [ 52.424273] a.out invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL), nodemask=(null), order=0, oom_score_adj=-1000 lines which Michal's patch cannot suppress. Also, my console is console=ttyS0,115200n8 . Not slow at all. > > NAK to your patch. I think you're looking at this from the wrong > angle. A console that takes almost 4 minutes to print 70k lines > shouldn't be the baseline for how verbose KERN_INFO is. > Run the testcase in your environment.