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 B460E6B026D for ; Wed, 15 Nov 2017 09:57:19 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id x66so8299652pfe.21 for ; Wed, 15 Nov 2017 06:57:19 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id c7si17976971plo.298.2017.11.15.06.57.18 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 15 Nov 2017 06:57:18 -0800 (PST) Date: Wed, 15 Nov 2017 15:57:16 +0100 From: Michal Hocko Subject: Re: [PATCH] mm, meminit: Serially initialise deferred memory if trace_buf_size is specified Message-ID: <20171115145716.w34jaez5ljb3fssn@dhcp22.suse.cz> References: <20171115085556.fla7upm3nkydlflp@techsingularity.net> <20171115115559.rjb5hy6d6332jgjj@dhcp22.suse.cz> <20171115141329.ieoqvyoavmv6gnea@techsingularity.net> <20171115142816.zxdgkad3ch2bih6d@dhcp22.suse.cz> <20171115144314.xwdi2sbcn6m6lqdo@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171115144314.xwdi2sbcn6m6lqdo@techsingularity.net> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, yasu.isimatu@gmail.com, koki.sanagi@us.fujitsu.com On Wed 15-11-17 14:43:14, Mel Gorman wrote: > On Wed, Nov 15, 2017 at 03:28:16PM +0100, Michal Hocko wrote: > > On Wed 15-11-17 14:13:29, Mel Gorman wrote: > > [...] > > > I doubt anyone well. Even the original reporter appeared to pick that > > > particular value just to trigger the OOM. > > > > Then why do we care at all? The trace buffer size can be configured from > > the userspace if it is not sufficiently large IIRC. > > > > I guess there is the potential that the trace buffer needs to be large > enough early on in boot but I'm not sure why it would need to be that large > to be honest. Bottom line, it's fairly trivial to just serialise meminit > in the event that it's resized from command line. I'm also ok with just > leaving this is as a "don't set the buffer that large" I would be reluctant to touch the code just because of insane kernel command line option. That being said, I will not object or block the patch it just seems unnecessary for most reasonable setups I can think of. If there is a legitimate usage of such a large trace buffer then I wouldn't oppose. -- Michal Hocko SUSE Labs -- 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