From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 9EB2B6B0011 for ; Fri, 6 May 2011 09:10:00 -0400 (EDT) Date: Fri, 6 May 2011 14:09:55 +0100 From: Mel Gorman Subject: Re: [PATCH]mm/compation.c: checking page in lru twice Message-ID: <20110506130955.GF4941@csn.ul.ie> References: <1304681575.15473.4.camel@figo-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1304681575.15473.4.camel@figo-desktop> Sender: owner-linux-mm@kvack.org List-ID: To: "Figo.zhang" Cc: lkml , "linux-mm@kvack.org" , kamezawa.hiroyu@jp.fujisu.com, minchan.kim@gmail.com, Andrew Morton , aarcange@redhat.com On Fri, May 06, 2011 at 07:32:46PM +0800, Figo.zhang wrote: > > in isolate_migratepages() have check page in LRU twice, the next one > at _isolate_lru_page(). > > Signed-off-by: Figo.zhang Not checking for PageLRU means that PageTransHuge() gets called for each page. While the scanner is active and the lock released, a transparent hugepage can be created and potentially we test PageTransHuge() on a tail page. This will trigger a BUG if CONFIG_DEBUG_VM is set. Nacked-by: Mel Gorman > > mm/compaction.c | 3 --- > 1 files changed, 0 insertions(+), 3 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 021a296..ac605cb 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -321,9 +321,6 @@ static unsigned long isolate_migratepages(struct zone *zone, > continue; > } > > - if (!PageLRU(page)) > - continue; > - > /* > * PageLRU is set, and lru_lock excludes isolation, > * splitting and collapsing (collapsing has already > > -- Mel Gorman SUSE Labs -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org