From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [patch 09/11] mm, page_alloc: allow system oom handlers to use memory reserves Date: Thu, 6 Mar 2014 16:13:37 -0500 Message-ID: <20140306211337.GC17902@htj.dyndns.org> References: Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=qxKHP7vdJmpOyCfhdGE1qAzlNblc/2GIldACVAUyJEw=; b=qiPvCOE+RVGSZreZt2H2teSeMvcc47ZbG2jqefpBdwH3R2iuOtbBqD7TWTgGwQ1bN2 B878fSxRRTSTVGpavlfqmoubXnI1bq5/FOMn1pTpm2LkdrOLOvDPDM0+QpUYZzpPe9iH baGAmcnKsDEc1kk4/lhOdh5RVpLyE8NLYiQCm8G//aU2NPhPI0UN7e5H5kjvGBnP5wRl 3Xw/nEkevcNxkrNq7yF5vaqh2nTKKO6//kmt3uzpu9qox9kv3AYrBDM25goUQPALrVPm +WCdFVhu2SNmNuICfj2XSADYq+vtfM2xMexz90M5LyXqFSDs/qe+R32OuTDGUCT9ZG2L 4D2A== Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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