From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 8ADE26B004D for ; Thu, 11 Jun 2009 11:06:22 -0400 (EDT) Date: Thu, 11 Jun 2009 16:06:27 +0100 From: Mel Gorman Subject: Re: [PATCH 1/3] remove wrong rotation at lumpy reclaim Message-ID: <20090611150627.GH7302@csn.ul.ie> References: <20090611165535.cf46bf29.kamezawa.hiroyu@jp.fujitsu.com> <20090611170018.c3758488.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20090611170018.c3758488.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "kosaki.motohiro@jp.fujitsu.com" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , "akpm@linux-foundation.org" , apw@canonical.com, riel@redhat.com, minchan.kim@gmail.com List-ID: On Thu, Jun 11, 2009 at 05:00:18PM +0900, KAMEZAWA Hiroyuki wrote: > From: KAMEZAWA Hiroyuki > > At lumpy reclaim, a page failed to be taken by __isolate_lru_page() can > be pushed back to "src" list by list_move(). But the page may not be from > "src" list. And list_move() itself is unnecessary because the page is > not on top of LRU. Then, leave it as it is if __isolate_lru_page() fails. > > This patch doesn't change the logic as "we should exit loop or not" and > just fixes buggy list_move(). > > Signed-off-by: KAMEZAWA Hiroyuki > --- > mm/vmscan.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > > Index: lumpy-reclaim-trial/mm/vmscan.c > =================================================================== > --- lumpy-reclaim-trial.orig/mm/vmscan.c > +++ lumpy-reclaim-trial/mm/vmscan.c > @@ -936,18 +936,11 @@ static unsigned long isolate_lru_pages(u > /* Check that we have not crossed a zone boundary. */ > if (unlikely(page_zone_id(cursor_page) != zone_id)) > continue; > - switch (__isolate_lru_page(cursor_page, mode, file)) { > - case 0: > + if (__isolate_lru_page(cursor_page, mode, file) == 0) { > list_move(&cursor_page->lru, dst); > nr_taken++; > scan++; > break; > - > - case -EBUSY: > - /* else it is being freed elsewhere */ > - list_move(&cursor_page->lru, src); > - default: > - break; /* ! on LRU or wrong list */ > } > } > } > At very minimum, this avoids an unnecessary reshuffling of the LRU lists during lumpy reclaim. Thanks Acked-by: Mel Gorman -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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