Messages in this thread | | | Date | Tue, 16 Aug 2016 11:23:45 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 1/3] mm: fix set pageblock migratetype in deferred struct page init |
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On Tue 16-08-16 16:56:54, Xishi Qiu wrote: > On 2016/8/16 16:41, Michal Hocko wrote: > > > On Thu 04-08-16 19:25:03, Xishi Qiu wrote: > >> MAX_ORDER_NR_PAGES is usually 4M, and a pageblock is usually 2M, so we only > >> set one pageblock's migratetype in deferred_free_range() if pfn is aligned > >> to MAX_ORDER_NR_PAGES. > > > > Do I read the changelog correctly and the bug causes leaking unmovable > > allocations into movable zones? > > Hi Michal, > > This bug will cause uninitialized migratetype, you can see from > "cat /proc/pagetypeinfo", almost half blocks are Unmovable.
Please add that information to the changelog. Leaking unmovable allocations to the movable zones defeats the whole purpose of the movable zone so I guess we really want to mark this for stable. AFAICS it should also note: Fixes: ac5d2539b238 ("mm: meminit: reduce number of times pageblocks are set during struct page init") and stable 4.2+
-- Michal Hocko SUSE Labs
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