From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) by kanga.kvack.org (Postfix) with ESMTP id 52CD06B0003 for ; Thu, 18 Oct 2018 19:54:34 -0400 (EDT) Received: by mail-pg1-f198.google.com with SMTP id 75-v6so2218830pgc.13 for ; Thu, 18 Oct 2018 16:54:34 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id 19-v6sor11995409pgv.22.2018.10.18.16.54.33 for (Google Transport Security); Thu, 18 Oct 2018 16:54:33 -0700 (PDT) Date: Fri, 19 Oct 2018 08:54:27 +0900 From: Sergey Senozhatsky Subject: Re: [PATCH v3] mm: memcontrol: Don't flood OOM messages with no eligible task. Message-ID: <20181018235427.GA877@jagdpanzerIV> References: <201810180246.w9I2koi3011358@www262.sakura.ne.jp> <20181018042739.GA650@jagdpanzerIV> <201810180526.w9I5QvVn032670@www262.sakura.ne.jp> <20181018061018.GB650@jagdpanzerIV> <20181018075611.GY18839@dhcp22.suse.cz> <20181018081352.GA438@jagdpanzerIV> <2c2b2820-e6f8-76c8-c431-18f60845b3ab@i-love.sakura.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2c2b2820-e6f8-76c8-c431-18f60845b3ab@i-love.sakura.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: Sergey Senozhatsky , Michal Hocko , Johannes Weiner , 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 , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , syzbot On (10/18/18 20:58), Tetsuo Handa wrote: > > > > A knob might do. > > As well as /proc/sys/kernel/printk tweaks, probably. One can even add > > echo "a b c d" > /proc/sys/kernel/printk to .bashrc and adjust printk > > console levels on login and rollback to old values in .bash_logout > > May be. > > That can work for only single login with root user case. > Not everyone logs into console as root user. Add sudo ;) > It is pity that we can't send kernel messages to only selected consoles > (e.g. all messages are sent to netconsole, but only critical messages are > sent to local consoles). OK, that's a fair point. There was a patch from FB, which would allow us to set a log_level on per-console basis. So the noise goes to heav^W net console; only critical stuff goes to the serial console (if I recall it correctly). I'm not sure what happened to that patch, it was a while ago. I'll try to find that out. [..] > That boils down to a "user interaction" problem. > Not limiting > > "%s invoked oom-killer: gfp_mask=%#x(%pGg), nodemask=%*pbl, order=%d, oom_score_adj=%hd\n" > "Out of memory and no killable processes...\n" > > is very annoying. > > And I really can't understand why Michal thinks "handling this requirement" as > "make the code more complex than necessary and squash different things together". Michal is trying very hard to address the problem in a reasonable way. The problem you are talking about is not MM specific. You can have a faulty SCSI device, corrupted FS, and so and on. -ss