Re: [PATCH -mm V3] do_migrate_pages() calls migrate_to_node() even if task is already on a correct node

Rik van Riel
2012-04-26T18:15:51Z

On 04/26/2012 02:11 PM, Larry Woodman wrote:

> This patch changes do_migrate_pages() to only preserve the relative
> layout inside the
> program if the number of NUMA nodes in the source and destination mask
> are the
> same. If the number is different, we do a much more efficient migration
> by not touching
> memory that is in an allowed node.
>
> This preserves the old behaviour for programs that want it, while
> allowing a userspace
> NUMA placement tool to use the new, faster migration. This improves
> performance in
> our tests by up to a factor of 7.

> Signed-off-by: Larry Woodman<lwoodman@redhat.com>

Reviewed-by: Rik van Riel <riel@redhat.com>