Re: [PATCH] mm: use migrate_prep() instead of migrate_prep_local()

From: Michal Nazarewicz
Date: Mon Nov 12 2012 - 11:52:10 EST


On Mon, Nov 12 2012, Marek Szyprowski wrote:
> __alloc_contig_migrate_range() should use all possible ways to get all the
> pages migrated from the given memory range, so pruning per-cpu lru lists
> for all CPUs is required, regadless the cost of such operation. Otherwise
> some pages which got stuck at per-cpu lru list might get missed by
> migration procedure causing the contiguous allocation to fail.
>
> Reported-by: SeongHwan Yoon <sunghwan.yun@xxxxxxxxxxx>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>

Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>

> ---
> mm/page_alloc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 1bfe2b0..fcb9719 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5677,7 +5677,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
> unsigned int tries = 0;
> int ret = 0;
>
> - migrate_prep_local();
> + migrate_prep();
>
> while (pfn < end || !list_empty(&cc->migratepages)) {
> if (fatal_signal_pending(current)) {

--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, MichaÅ âmina86â Nazarewicz (o o)
ooo +----<email/xmpp: mpn@xxxxxxxxxx>--------------ooO--(_)--Ooo--

Attachment: pgp00000.pgp
Description: PGP signature