From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754577Ab2GYPrv (ORCPT ); Wed, 25 Jul 2012 11:47:51 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:47839 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754046Ab2GYPrt (ORCPT ); Wed, 25 Jul 2012 11:47:49 -0400 Date: Wed, 25 Jul 2012 08:47:45 -0700 From: Greg KH To: Mel Gorman Cc: Stable , Linux-MM , LKML Subject: Re: [PATCH 16/34] mm: compaction: Allow compaction to isolate dirty pages Message-ID: <20120725154745.GB18901@kroah.com> References: <1343050727-3045-1-git-send-email-mgorman@suse.de> <1343050727-3045-17-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1343050727-3045-17-git-send-email-mgorman@suse.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 23, 2012 at 02:38:29PM +0100, Mel Gorman wrote: > commit a77ebd333cd810d7b680d544be88c875131c2bd3 upstream. > > Stable note: Not tracked in Bugzilla. A fix aimed at preserving page aging > information by reducing LRU list churning had the side-effect of > reducing THP allocation success rates. This was part of a series > to restore the success rates while preserving the reclaim fix. > > Commit [39deaf85: mm: compaction: make isolate_lru_page() filter-aware] > noted that compaction does not migrate dirty or writeback pages and > that is was meaningless to pick the page and re-add it to the LRU list. > > What was missed during review is that asynchronous migration moves > dirty pages if their ->migratepage callback is migrate_page() because > these can be moved without blocking. This potentially impacted > hugepage allocation success rates by a factor depending on how many > dirty pages are in the system. > > This patch partially reverts 39deaf85 to allow migration to isolate > dirty pages again. This increases how much compaction disrupts the > LRU but that is addressed later in the series. > > Signed-off-by: Mel Gorman > Reviewed-by: Andrea Arcangeli > Reviewed-by: Rik van Riel > Reviewed-by: Minchan Kim Note, the changelog here differs from what is in Linus's tree by a LOT. I took the version in Linus's tree instead. greg k-h