From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 7C5226B023D for ; Tue, 15 Jun 2010 10:37:59 -0400 (EDT) Message-ID: <4C1787DF.3020102@redhat.com> Date: Tue, 15 Jun 2010 10:02:07 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 12/12] vmscan: Do not writeback pages in direct reclaim References: <1276514273-27693-1-git-send-email-mel@csn.ul.ie> <1276514273-27693-13-git-send-email-mel@csn.ul.ie> <4C16A567.4080000@redhat.com> <20100615114510.GE26788@csn.ul.ie> <4C17815A.8080402@redhat.com> <20100615133727.GA27980@infradead.org> In-Reply-To: <20100615133727.GA27980@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Christoph Hellwig Cc: Mel Gorman , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Johannes Weiner , KAMEZAWA Hiroyuki , Andrew Morton List-ID: On 06/15/2010 09:37 AM, Christoph Hellwig wrote: > On Tue, Jun 15, 2010 at 09:34:18AM -0400, Rik van Riel wrote: >> If direct reclaim can overflow the stack, so can direct >> memcg reclaim. That means this patch does not solve the >> stack overflow, while admitting that we do need the >> ability to get specific pages flushed to disk from the >> pageout code. > > Can you explain what the hell memcg reclaim is and why it needs > to reclaim from random contexts? The page fault code will call the cgroup accounting code. When a cgroup goes over its memory limit, __mem_cgroup_try_charge will call mem_cgroup_hierarchical_reclaim, which will then go into the page reclaim code. > It seems everything that has a cg in it's name that I stumbled over > lately seems to be some ugly wart.. No argument there. It took me a few minutes to find the code path above :) -- All rights reversed -- 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