Re: [PATCH 3/3] mm: slub: Default slub_max_order to 0

Mel Gorman
2011-05-13T09:50:09Z

On Thu, May 12, 2011 at 08:00:18PM +0200, Andrea Arcangeli wrote:
> <SNIP>
>
> BTW, it comes to mind in patch 2, SLUB should clear __GFP_REPEAT too
> (not only __GFP_NOFAIL). Clearing __GFP_WAIT may be worth it or not
> with COMPACTION=y, definitely good idea to clear __GFP_WAIT unless
> lumpy is restricted to __GFP_REPEAT|__GFP_NOFAIL.

This is in V2 (unreleased, testing in progress and was running
overnight). I noticed that clearing __GFP_REPEAT is required for
reclaim/compaction if direct reclaimers from SLUB are to return false in
should_continue_reclaim() and bail out from high-order allocation
properly. As it is, there is a possibility for slub high-order direct
reclaimers to loop in reclaim/compaction for a long time. This is
only important when CONFIG_COMPACTION=y.

--
Mel Gorman
SUSE Labs