Re: [PATCH 04/14] mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED

2016-04-21 Thread Hillf Danton
> > From: Michal Hocko > > try_to_compact_pages can currently return COMPACT_SKIPPED even when the > compaction is defered for some zone just because zone DMA is skipped > in 99% of cases due to watermark checks. This makes COMPACT_DEFERRED > basically unusable for the page allocator as a feedba

[PATCH 04/14] mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED

2016-04-20 Thread Michal Hocko
From: Michal Hocko try_to_compact_pages can currently return COMPACT_SKIPPED even when the compaction is defered for some zone just because zone DMA is skipped in 99% of cases due to watermark checks. This makes COMPACT_DEFERRED basically unusable for the page allocator as a feedback mechanism.