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SubjectRe: [PATCHv21 08/16] mm: mmzone: MIGRATE_CMA migration type added
On Fri, 10 Feb 2012 18:32:23 +0100
Marek Szyprowski <m.szyprowski@samsung.com> wrote:

> From: Michal Nazarewicz <mina86@mina86.com>
>
> 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@mina86.com>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> Acked-by: Mel Gorman <mel@csn.ul.ie>
> Tested-by: Rob Clark <rob.clark@linaro.org>
> Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>



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