Re: [PATCH] mm: page_alloc: High-order per-cpu page allocator v3
From: Johannes Weiner <hannes@cmpxchg.org>
Date: 2016-11-28 19:54:43
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On Sun, Nov 27, 2016 at 01:19:54PM +0000, Mel Gorman wrote:
While it is recognised that this is a mixed bag of results, the patch helps a lot more workloads than it hurts and intuitively, avoiding the zone->lock in some cases is a good thing. Signed-off-by: Mel Gorman <redacted>
This seems like a net gain to me, and the patch loos good too. Acked-by: Johannes Weiner <hannes@cmpxchg.org>
quoted hunk ↗ jump to hunk
@@ -255,6 +255,24 @@ enum zone_watermarks { NR_WMARK }; +/* + * One per migratetype for order-0 pages and one per high-order up to + * and including PAGE_ALLOC_COSTLY_ORDER. This may allow unmovable + * allocations to contaminate reclaimable pageblocks if high-order + * pages are heavily used.
I think that should be fine. Higher order allocations rely on being able to compact movable blocks, not on reclaim freeing contiguous blocks, so poisoning reclaimable blocks is much less of a concern than poisoning movable blocks. And I'm not aware of any 0 < order < COSTLY movable allocations that would put movable blocks into an HO cache. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>