Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754736Ab0F2MwE (ORCPT ); Tue, 29 Jun 2010 08:52:04 -0400 Received: from gir.skynet.ie ([193.1.99.77]:48295 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754278Ab0F2MwC (ORCPT ); Tue, 29 Jun 2010 08:52:02 -0400 Date: Tue, 29 Jun 2010 13:51:43 +0100 From: Mel Gorman To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Rik van Riel , Johannes Weiner , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Andrew Morton , Andrea Arcangeli Subject: Re: [PATCH 14/14] fs,xfs: Allow kswapd to writeback pages Message-ID: <20100629125143.GB31561@csn.ul.ie> References: <1277811288-5195-1-git-send-email-mel@csn.ul.ie> <1277811288-5195-15-git-send-email-mel@csn.ul.ie> <20100629123722.GA725@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100629123722.GA725@infradead.org> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1575 Lines: 37 On Tue, Jun 29, 2010 at 08:37:22AM -0400, Christoph Hellwig wrote: > I don't see a patch in this set which refuses writeback from the memcg > context, which we identified as having large stack footprint in hte > discussion of the last patch set. > It wasn't clear to me what the right approach was there and should have noted that in the intro. The last note I have on it is this message http://kerneltrap.org/mailarchive/linux-kernel/2010/6/17/4584087 which might avoid the deep stack usage but I wasn't 100% sure. As kswapd doesn't clean pages for memcg, I left memcg being able to direct writeback to see what the memcg people preferred. > Meanwhile I've submitted a patch to xfs to allow reclaim from kswapd, > and just prevent it from direct and memcg reclaim. > Good stuff. > Btw, it might be worth to also allow kswap to all writeout on ext4, > but doing that will be a bit more complicated than the btrfs and xfs > variants as the code is rather convoluted. > Fully agreed. I looked into it and got caught in its twisty web so postponed it until this much can be finalised, agreed upon or rejected - all pre-requisities to making the ext4 work worthwhile. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/