lkml.org 
[lkml]   [2011]   [Jun]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] mm: compaction: fix special case -1 order checks
On Mon, May 30, 2011 at 05:24:50PM +0200, Michal Hocko wrote:
> <SNIP>
> mm: compaction: fix special case -1 order checks
>
> 56de7263 (mm: compaction: direct compact when a high-order allocation
> fails) introduced a check for cc->order == -1 in compact_finished. We
> should continue compacting in that case because the request came from
> userspace and there is no particular order to compact for.
> Similar check has been added by 82478fb7 (mm: compaction:
> prevent division-by-zero during user-requested compaction) for
> compaction_suitable.
>
> The check is, however, done after zone_watermark_ok which uses order as
> a right hand argument for shifts. Not only watermark check is pointless
> if we can break out without it but it also uses 1 << -1 which is not
> well defined (at least from C standard). Let's move the -1 check above
> zone_watermark_ok.
>
> [Minchan Kim <minchan.kim@gmail.com> - caught compaction_suitable]
> Signed-off-by: Michal Hocko <mhocko@suse.cz>
> Cc: Mel Gorman <mgorman@suse.de>

Acked-by: Mel Gorman <mgorman@suse.de>

--
Mel Gorman
SUSE Labs


\
 
 \ /
  Last update: 2011-06-02 12:41    [from the cache]
©2003-2011 Jasper Spaans