Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757526Ab0DRTf4 (ORCPT ); Sun, 18 Apr 2010 15:35:56 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:46222 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751375Ab0DRTfz (ORCPT ); Sun, 18 Apr 2010 15:35:55 -0400 Date: Sun, 18 Apr 2010 15:35:45 -0400 From: Christoph Hellwig To: Andrew Morton Cc: Christoph Hellwig , Mel Gorman , Dave Chinner , KOSAKI Motohiro , Chris Mason , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] mm: disallow direct reclaim page writeback Message-ID: <20100418193545.GA28479@infradead.org> References: <20100414155233.D153.A69D9226@jp.fujitsu.com> <20100414072830.GK2493@dastard> <20100414085132.GJ25756@csn.ul.ie> <20100415013436.GO2493@dastard> <20100415102837.GB10966@csn.ul.ie> <20100416041412.GY2493@dastard> <20100416151403.GM19264@csn.ul.ie> <20100417203239.dda79e88.akpm@linux-foundation.org> <20100418190526.GA1692@infradead.org> <20100418123109.0953b7a5.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100418123109.0953b7a5.akpm@linux-foundation.org> User-Agent: Mutt/1.5.19 (2009-01-05) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 934 Lines: 19 On Sun, Apr 18, 2010 at 12:31:09PM -0400, Andrew Morton wrote: > Yeah, but it's all bandaids. The first thing we should do is work out > why writeout-off-the-LRU increased so much and fix that. > > Handing writeout off to separate threads might be used to solve the > stack consumption problem but we shouldn't use it to "solve" the > excess-writeout-from-page-reclaim problem. I think both of them are really serious issue. Exposing the whole stack and lock problems with direct reclaim are a bit of a positive side-effect os the writeout tuning messup. Without it the problems would still be just as harmfull, just happenening even less often and thus getting even less attention. -- 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/