From: Andrew Morton <akpm@linux-foundation.org>
To: Mel Gorman <mel@csn.ul.ie>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kamezawa.hiroyu@jp.fujitsu.com, apw@shadowen.org
Subject: Re: [PATCH] Mark the correct zone as full when scanning zonelists
Date: Thu, 11 Sep 2008 14:41:55 -0700 [thread overview]
Message-ID: <20080911144155.c70ef145.akpm@linux-foundation.org> (raw)
In-Reply-To: <20080911212550.GA18087@csn.ul.ie>
On Thu, 11 Sep 2008 22:25:51 +0100
Mel Gorman <mel@csn.ul.ie> wrote:
> The for_each_zone_zonelist() uses a struct zoneref *z cursor when scanning
> zonelists to keep track of where in the zonelist it is. The zoneref that
> is returned corresponds to the the next zone that is to be scanned, not
> the current one as it originally thought of as an opaque list.
>
> When the page allocator is scanning a zonelist, it marks zones that it
> temporarily full zones to eliminate near-future scanning attempts.
That sentence needs help.
> It uses
> the zoneref for the marking and consequently the incorrect zone gets marked
> full. This leads to a suitable zone being skipped in the mistaken belief
> it is full. This patch corrects the problem by changing zoneref to be the
> current zone being scanned instead of the next one.
Applicable to 2.6.26 as well, yes?
Someone reported a bug a few weeks ago which I think this patch will fix,
yes? I don't remember who that was, nor do I recall the precise details
of what the userspace-visible (mis)behaviour was.
Are you able to fill in the gaps here? Put yourself in the position of
a poor little -stable maintainer scratching his head wondering ytf he
was sent this patch.
Thanks.
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next prev parent reply other threads:[~2008-09-11 21:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-11 21:25 Mel Gorman
2008-09-11 21:41 ` Andrew Morton [this message]
2008-09-12 1:10 ` KAMEZAWA Hiroyuki
2008-09-12 20:37 ` Mel Gorman
2008-09-12 18:58 ` Mel Gorman
2008-09-15 23:20 ` Mel Gorman
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