On Wed, Jun 05, 2013 at 05:10:35PM +0200, Andrea Arcangeli wrote: > Require more high order pages in the watermarks, to give more margin > for concurrent allocations. If there are too few pages, they can > disappear too soon. > > Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> This seems to be special casing THP allocations to allow it to relax the watermark requirements. FWIW, I have seen cases where hugepage allocations fail even though there are pages free becase memory is low overall. It was very marginal though in terms of overall success rates but that was also a long time ago when I was checking. How much of a difference did you see with this patch? -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>