From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f172.google.com (mail-qc0-f172.google.com [209.85.216.172]) by kanga.kvack.org (Postfix) with ESMTP id 113FF6B0031 for ; Thu, 6 Mar 2014 16:13:41 -0500 (EST) Received: by mail-qc0-f172.google.com with SMTP id i8so3742112qcq.31 for ; Thu, 06 Mar 2014 13:13:40 -0800 (PST) Received: from mail-qa0-x231.google.com (mail-qa0-x231.google.com [2607:f8b0:400d:c00::231]) by mx.google.com with ESMTPS id a10si1147377qcs.2.2014.03.06.13.13.40 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 06 Mar 2014 13:13:40 -0800 (PST) Received: by mail-qa0-f49.google.com with SMTP id cm18so3040659qab.22 for ; Thu, 06 Mar 2014 13:13:40 -0800 (PST) Date: Thu, 6 Mar 2014 16:13:37 -0500 From: Tejun Heo Subject: Re: [patch 09/11] mm, page_alloc: allow system oom handlers to use memory reserves Message-ID: <20140306211337.GC17902@htj.dyndns.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Andrew Morton , Johannes Weiner , Michal Hocko , KAMEZAWA Hiroyuki , Christoph Lameter , Pekka Enberg , Mel Gorman , Oleg Nesterov , Rik van Riel , Jianguo Wu , Tim Hockin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org On Tue, Mar 04, 2014 at 07:59:35PM -0800, David Rientjes wrote: > The root memcg allows unlimited memory charging, so no memory may be > reserved for userspace oom handlers that are responsible for dealing > with system oom conditions. > > Instead, this memory must come from per-zone memory reserves. This > allows the memory allocation to succeed, and the memcg charge will > naturally succeed afterwards. > > This patch introduces per-zone oom watermarks that aren't really > watermarks in the traditional sense. The oom watermark is the root > memcg's oom reserve proportional to the size of the zone. When a page > allocation is done, the effective watermark is > > [min/low/high watermark] - [oom watermark] > > For the [min watermark] case, this is effectively the oom reserve. > However, it also adjusts the low and high watermark accordingly so > memory is actually only allocated from min reserves when appropriate. > > Signed-off-by: David Rientjes Until consensus on the whole approach can be reached, Nacked-by: Tejun Heo Thanks. -- 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