Messages in this thread | | | Date | Thu, 13 Mar 2014 14:25:40 +0000 | From | Mel Gorman <> | Subject | Re: [RFC][PATCH v2] mm/page_alloc: fix freeing of MIGRATE_RESERVE migratetype pages |
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On Fri, Feb 14, 2014 at 07:34:17PM +0100, Bartlomiej Zolnierkiewicz wrote: > Pages allocated from MIGRATE_RESERVE migratetype pageblocks > are not freed back to MIGRATE_RESERVE migratetype free > lists in free_pcppages_bulk()->__free_one_page() if we got > to free_pcppages_bulk() through drain_[zone_]pages(). > The freeing through free_hot_cold_page() is okay because > freepage migratetype is set to pageblock migratetype before > calling free_pcppages_bulk(). If pages of MIGRATE_RESERVE > migratetype end up on the free lists of other migratetype > whole Reserved pageblock may be later changed to the other > migratetype in __rmqueue_fallback() and it will be never > changed back to be a Reserved pageblock. Fix the issue by > preserving freepage migratetype as a pageblock migratetype > (instead of overriding it to the requested migratetype) > for MIGRATE_RESERVE migratetype pages in rmqueue_bulk(). > > The problem was introduced in v2.6.31 by commit ed0ae21 > ("page allocator: do not call get_pageblock_migratetype() > more than necessary"). > > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> > Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> > Cc: Marek Szyprowski <m.szyprowski@samsung.com> > Cc: Mel Gorman <mgorman@suse.de> > Cc: Hugh Dickins <hughd@google.com>
It's a pity about the unconditional pageblock lookup in that path but I didn't see a better way around it so
Acked-by: Mel Gorman <mgorman@suse.de>
-- Mel Gorman SUSE Labs
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