Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759218Ab0FKRtK (ORCPT ); Fri, 11 Jun 2010 13:49:10 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:47226 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756286Ab0FKRtI (ORCPT ); Fri, 11 Jun 2010 13:49:08 -0400 Date: Fri, 11 Jun 2010 13:49:00 -0400 From: Christoph Hellwig To: Andrew Morton Cc: Christoph Hellwig , Mel Gorman , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Rik van Riel Subject: Re: [PATCH 6/6] vmscan: Do not writeback pages in direct reclaim Message-ID: <20100611174900.GA32761@infradead.org> References: <1275987745-21708-1-git-send-email-mel@csn.ul.ie> <1275987745-21708-7-git-send-email-mel@csn.ul.ie> <20100610231706.1d7528f2.akpm@linux-foundation.org> <20100611162523.GA24707@infradead.org> <20100611104331.d8463580.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100611104331.d8463580.akpm@linux-foundation.org> User-Agent: Mutt/1.5.20 (2009-08-17) 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: 882 Lines: 17 On Fri, Jun 11, 2010 at 10:43:31AM -0700, Andrew Morton wrote: > Of course, but making a change like that in the current VM will cause a > large number of dirty pages to get refiled, so the impact of this > change on some workloads could be quite bad. Note that ext4, btrfs and xfs all error out on ->writepage from reclaim context. That is both kswapd and direct reclaim because there is no way to distinguish between the two. Things seem to work fine with these filesystems, so the issue can't be _that_ bad. Of course reducing this to just error out from direct reclaim, and fixing them VM to better cope with it is even better. -- 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/