[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20071214115038.GB11046@csn.ul.ie>
Date: Fri, 14 Dec 2007 11:50:39 +0000
From: Mel Gorman <mel@....ul.ie>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Mark Lord <liml@....ca>, James.Bottomley@...senPartnership.com,
jens.axboe@...cle.com, lkml@....ca, matthew@....cx,
linux-ide@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-scsi@...r.kernel.org, linux-mm@...ck.org
Subject: Re: QUEUE_FLAG_CLUSTER: not working in 2.6.24 ?
On (13/12/07 16:37), Andrew Morton didst pronounce:
> On Thu, 13 Dec 2007 19:30:00 -0500
> Mark Lord <liml@....ca> wrote:
>
> > Here's the commit that causes the regression:
> >
> > ...
> >
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -760,7 +760,8 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
> > struct page *page = __rmqueue(zone, order, migratetype);
> > if (unlikely(page == NULL))
> > break;
> > - list_add_tail(&page->lru, list);
> > + list_add(&page->lru, list);
>
> well that looks fishy.
>
The reasoning behind the change was the first page encountered on the list
by the caller would have a matching migratetype. I failed to take into
account the physical ordering of pages returned. I'm setting up to run some
performance benchmarks of the candidate fix merged into the -mm tree to see
if the search shows up or not. I'm testing against 2.6.25-rc5 but it'll
take a few hours to complete.
--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists