On Fri, 10 Feb 2012 18:32:23 +0100 Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote: > From: Michal Nazarewicz <mina86@xxxxxxxxxx> > > The MIGRATE_CMA migration type has two main characteristics: > (i) only movable pages can be allocated from MIGRATE_CMA > pageblocks and (ii) page allocator will never change migration > type of MIGRATE_CMA pageblocks. > > This guarantees (to some degree) that page in a MIGRATE_CMA page > block can always be migrated somewhere else (unless there's no > memory left in the system). > > It is designed to be used for allocating big chunks (eg. 10MiB) > of physically contiguous memory. Once driver requests > contiguous memory, pages from MIGRATE_CMA pageblocks may be > migrated away to create a contiguous block. > > To minimise number of migrations, MIGRATE_CMA migration type > is the last type tried when page allocator falls back to other > migration types when requested. > > Signed-off-by: Michal Nazarewicz <mina86@xxxxxxxxxx> > Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > Acked-by: Mel Gorman <mel@xxxxxxxxx> > Tested-by: Rob Clark <rob.clark@xxxxxxxxxx> > Tested-by: Ohad Ben-Cohen <ohad@xxxxxxxxxx> > Tested-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>