changes for v2 o include more experiment data in cover letter o deal with vlastimil's comments mostly about commit description on 4/5 This patchset is related to the compaction. patch 1 fixes contrary implementation of the purpose of compaction. patch 2~4 are for optimization. patch 5 is just for clean-up. I tested this patchset with stress-highalloc benchmark on Mel's mmtest and cannot find any regression in terms of success rate. And I find much reduced(9%) elapsed time. Below is the average result of 10 runs on my 4GB quad core system. compaction-base+ is based on 3.13.0 with Vlastimil's recent fixes. compaction-fix+ has this patch series on top of compaction-base+. Thanks. stress-highalloc 3.13.0 3.13.0 compaction-base+ compaction-fix+ Success 1 14.10 15.00 Success 2 20.20 20.00 Success 3 68.30 73.40 3.13.0 3.13.0 compaction-base+ compaction-fix+ User 3486.02 3437.13 System 757.92 741.15 Elapsed 1638.52 1488.32 3.13.0 3.13.0 compaction-base+ compaction-fix+ Minor Faults 172591561 167116621 Major Faults 984 859 Swap Ins 743 653 Swap Outs 3657 3535 Direct pages scanned 129742 127344 Kswapd pages scanned 1852277 1817825 Kswapd pages reclaimed 1838000 1804212 Direct pages reclaimed 129719 127327 Kswapd efficiency 98% 98% Kswapd velocity 1130.066 1221.296 Direct efficiency 99% 99% Direct velocity 79.367 85.585 Percentage direct scans 6% 6% Zone normal velocity 231.829 246.097 Zone dma32 velocity 972.589 1055.158 Zone dma velocity 5.015 5.626 Page writes by reclaim 6287 6534 Page writes file 2630 2999 Page writes anon 3657 3535 Page reclaim immediate 2187 2080 Sector Reads 2917808 2877336 Sector Writes 11477891 11206722 Page rescued immediate 0 0 Slabs scanned 2214118 2168524 Direct inode steals 12181 9788 Kswapd inode steals 144830 132109 Kswapd skipped wait 0 0 THP fault alloc 0 0 THP collapse alloc 0 0 THP splits 0 0 THP fault fallback 0 0 THP collapse fail 0 0 Compaction stalls 738 714 Compaction success 194 207 Compaction failures 543 507 Page migrate success 1806083 1464014 Page migrate failure 0 0 Compaction pages isolated 3873329 3162974 Compaction migrate scanned 74594862 59874420 Compaction free scanned 125888854 110868637 Compaction cost 2469 1998 Joonsoo Kim (5): mm/compaction: disallow high-order page for migration target mm/compaction: do not call suitable_migration_target() on every page mm/compaction: change the timing to check to drop the spinlock mm/compaction: check pageblock suitability once per pageblock mm/compaction: clean-up code on success of ballon isolation mm/compaction.c | 75 ++++++++++++++++++++++++++++--------------------------- 1 file changed, 38 insertions(+), 37 deletions(-) -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>