From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-f169.google.com (mail-yk0-f169.google.com [209.85.160.169]) by kanga.kvack.org (Postfix) with ESMTP id A67556B0036 for ; Thu, 6 Mar 2014 16:12:50 -0500 (EST) Received: by mail-yk0-f169.google.com with SMTP id 142so8218172ykq.0 for ; Thu, 06 Mar 2014 13:12:50 -0800 (PST) Received: from mail-yh0-x229.google.com (mail-yh0-x229.google.com [2607:f8b0:4002:c01::229]) by mx.google.com with ESMTPS id 69si12423255yhf.97.2014.03.06.13.12.50 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 06 Mar 2014 13:12:50 -0800 (PST) Received: by mail-yh0-f41.google.com with SMTP id f73so3365428yha.28 for ; Thu, 06 Mar 2014 13:12:50 -0800 (PST) Date: Thu, 6 Mar 2014 16:12:46 -0500 From: Tejun Heo Subject: Re: [patch 07/11] mm, memcg: allow processes handling oom notifications to access reserves Message-ID: <20140306211246.GB17902@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 07:59:29PM -0800, David Rientjes wrote: > Now that a per-process flag is available, define it for processes that > handle userspace oom notifications. This is an optimization to avoid > mantaining a list of such processes attached to a memcg at any given time > and iterating it at charge time. > > This flag gets set whenever a process has registered for an oom > notification and is cleared whenever it unregisters. > > When memcg reclaim has failed to free any memory, it is necessary for > userspace oom handlers to be able to dip into reserves to pagefault text, > allocate kernel memory to read the "tasks" file, allocate heap, etc. > > System oom conditions are not addressed at this time, but the same per- > process flag can be used in the page allocator to determine if access > should be given to userspace oom handlers to per-zone memory reserves at > a later time once there is consensus. > > Signed-off-by: David Rientjes ntil 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