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 D246C6B0087 for ; Sat, 16 May 2009 09:47:05 -0400 (EDT) Date: Sat, 16 May 2009 21:47:18 +0800 From: Wu Fengguang Subject: Re: [PATCH 3/3] vmscan: merge duplicate code in shrink_active_list() Message-ID: <20090516134718.GA15263@localhost> References: <20090516090005.916779788@intel.com> <20090516090448.535217680@intel.com> <20090516133950.GA5775@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090516133950.GA5775@cmpxchg.org> Sender: owner-linux-mm@kvack.org To: Johannes Weiner Cc: Andrew Morton , LKML , Rik van Riel , Christoph Lameter , KOSAKI Motohiro , "peterz@infradead.org" , "tytso@mit.edu" , "linux-mm@kvack.org" , "elladan@eskimo.com" , "npiggin@suse.de" , "minchan.kim@gmail.com" List-ID: On Sat, May 16, 2009 at 09:39:50PM +0800, Johannes Weiner wrote: > On Sat, May 16, 2009 at 05:00:08PM +0800, Wu Fengguang wrote: > > The "move pages to active list" and "move pages to inactive list" > > code blocks are mostly identical and can be served by a function. > > > > Thanks to Andrew Morton for pointing this out. > > > > Note that buffer_heads_over_limit check will also be carried out > > for re-activated pages, which is slightly different from pre-2.6.28 > > kernels. Also, Rik's "vmscan: evict use-once pages first" patch > > could totally stop scans of active list when memory pressure is low. > > So the net effect could be, the number of buffer heads is now more > > likely to grow large. > > I don't think that this could be harmful. We just preserve the buffer > mappings of what we consider the working set and with low memory > pressure, as you say, this set is not big. > > As to stripping of reactivated pages: the only pages we re-activate > for now are those VM_EXEC mapped ones. Since we don't expect IO from > or to these pages, removing the buffer mappings in case they grow too > large should be okay, I guess. Agreed - and good analyzes, thanks! Fengguang > > CC: Rik van Riel > > Signed-off-by: Wu Fengguang > > Reviewed-by: Johannes Weiner -- 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