Re: [patch v2 1/4] mm, migration: add destination page freeing callback

Mel Gorman
2014-05-02T10:10:35Z

On Thu, May 01, 2014 at 02:35:37PM -0700, David Rientjes wrote:
> Memory migration uses a callback defined by the caller to determine how to
> allocate destination pages. When migration fails for a source page, however, it
> frees the destination page back to the system.
>
> This patch adds a memory migration callback defined by the caller to determine
> how to free destination pages. If a caller, such as memory compaction, builds
> its own freelist for migration targets, this can reuse already freed memory
> instead of scanning additional memory.
>
> If the caller provides a function to handle freeing of destination pages, it is
> called when page migration fails. Otherwise, it may pass NULL and freeing back
> to the system will be handled as usual. This patch introduces no functional
> change.
>
> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Signed-off-by: David Rientjes <rientjes@google.com>

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

--
Mel Gorman
SUSE Labs