Re: [PATCH 27/63] mm: numa: Scan pages with elevated page_mapcount

[Rik van Riel]

On 10/07/2013 06:29 AM, Mel Gorman wrote:
> Currently automatic NUMA balancing is unable to distinguish between false
> shared versus private pages except by ignoring pages with an elevated
> page_mapcount entirely. This avoids shared pages bouncing between the
> nodes whose task is using them but that is ignored quite a lot of data.
> 
> This patch kicks away the training wheels in preparation for adding support
> for identifying shared/private pages is now in place. The ordering is so
> that the impact of the shared/private detection can be easily measured. Note
> that the patch does not migrate shared, file-backed within vmas marked
> VM_EXEC as these are generally shared library pages. Migrating such pages
> is not beneficial as there is an expectation they are read-shared between
> caches and iTLB and iCache pressure is generally low.
> 
> Signed-off-by: Mel Gorman <mgorman@xxxxxxx>

Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>

-- 
All rights reversed
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/