On 06/22/2016 03:22 AM, David Rientjes wrote:
If the memory compaction free scanner cannot successfully split a free page (only possible due to per-zone low watermark), terminate the free scanner rather than continuing to scan memory needlessly. If the watermark is insufficient for a free page of order <= cc->order, then terminate the scanner since all future splits will also likely fail. This prevents the compaction freeing scanner from scanning all memory on very large zones (very noticeable for zones > 128GB, for instance) when all splits will likely fail while holding zone->lock. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
--- Based on Linus's tree Suggest including in 4.7 if anybody else agrees?
4.7 definitely. Stable is less clear especially if you say it won't apply cleanly, but if you're ready to handle it, sure. The rules now allow fixing glaring performance bugs.
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