在 2020/9/3 下午4:32, Alex Shi 写道: >> > I have run thpscale with 'always' defrag setting of THP. The Amean stddev is much > larger than a very little average run time reducing. > > But the left patch 4 could show the cmpxchg retry reduce from thousands to hundreds > or less. > > Subject: [PATCH v4 4/4] add cmpxchg tracing It's a typical result with the patchset: Performance counter stats for './run-mmtests.sh -c configs/config-workload-thpscale pageblock-c': 9,564 compaction:mm_compaction_isolate_migratepages 6,430 compaction:mm_compaction_isolate_freepages 5,287 compaction:mm_compaction_migratepages 45,299 compaction:mm_compaction_begin 45,299 compaction:mm_compaction_end 30,557 compaction:mm_compaction_try_to_compact_pages 95,540 compaction:mm_compaction_finished 149,379 compaction:mm_compaction_suitable 0 compaction:mm_compaction_deferred 0 compaction:mm_compaction_defer_compaction 3,949 compaction:mm_compaction_defer_reset 0 compaction:mm_compaction_kcompactd_sleep 0 compaction:mm_compaction_wakeup_kcompactd 0 compaction:mm_compaction_kcompactd_wake 68 pageblock:hit_cmpxchg 113.570974583 seconds time elapsed 14.664451000 seconds user 96.847116000 seconds sys It's 5.9-rc2 base kernel result: Performance counter stats for './run-mmtests.sh -c configs/config-workload-thpscale rc2-e': 15,920 compaction:mm_compaction_isolate_migratepages 20,523 compaction:mm_compaction_isolate_freepages 9,752 compaction:mm_compaction_migratepages 27,773 compaction:mm_compaction_begin 27,773 compaction:mm_compaction_end 16,391 compaction:mm_compaction_try_to_compact_pages 62,809 compaction:mm_compaction_finished 69,821 compaction:mm_compaction_suitable 0 compaction:mm_compaction_deferred 0 compaction:mm_compaction_defer_compaction 7,875 compaction:mm_compaction_defer_reset 0 compaction:mm_compaction_kcompactd_sleep 0 compaction:mm_compaction_wakeup_kcompactd 0 compaction:mm_compaction_kcompactd_wake 1,208 pageblock:hit_cmpxchg 116.440414591 seconds time elapsed 15.326913000 seconds user 103.752758000 seconds sys