Re: [PATCH v19 00/20] per memcg lru_lock

From: Daniel Jordan
Date: Thu Sep 24 2020 - 13:57:58 EST

On Thu, Sep 24, 2020 at 11:28:15AM +0800, Alex Shi wrote:
> The new version rebased on v5.9-rc6 with line by line review by Hugh Dickins.

These thpscale numbers are from a proto-v19, which now seems to be gone from
Alex Shi's github. Once again, this is a regression test where memcg is
enabled but not used. There's a reasonable amount of isolations from
compaction as expected, as well as reclaim to a lesser extent.

I confined the runs to one node of a two-socket broadwell server, the same
machine as my other results. thpscale's total_size argument is about 80% of
the node's memory, its madvise option was enabled, and the system's thp
settings are enabled=always and defrag=madvise.

Both base and lru kernels show huge variance run to run, which is surprising
because I was expecting a microbenchmark like this to be more stable. There
seems to be an overall decrease in mean fault latency with the lru changes, but
it's in the noise, so it's hard to say how much of an improvement it really is.

I only ran up to four threads so these would be ready before I left. I'll be
away for a few days.


thpscale Fault Latencies
thp thp thp thp
base1 base2 lru1 lru2
Min fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Min fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Min fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Min fault-huge-1 214.00 ( 0.00%) 227.00 ( -6.07%) 235.00 ( -9.81%) 240.00 ( -12.15%)
Min fault-huge-3 321.00 ( 0.00%) 366.00 ( -14.02%) 323.00 ( -0.62%) 407.00 ( -26.79%)
Min fault-huge-4 441.00 ( 0.00%) 401.00 ( 9.07%) 525.00 ( -19.05%) 434.00 ( 1.59%)
Min fault-both-1 214.00 ( 0.00%) 227.00 ( -6.07%) 235.00 ( -9.81%) 240.00 ( -12.15%)
Min fault-both-3 321.00 ( 0.00%) 366.00 ( -14.02%) 323.00 ( -0.62%) 407.00 ( -26.79%)
Min fault-both-4 441.00 ( 0.00%) 401.00 ( 9.07%) 525.00 ( -19.05%) 434.00 ( 1.59%)
Amean fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Amean fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Amean fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Amean fault-huge-1 1549.55 ( 0.00%) 1667.13 * -7.59%* 1361.50 * 12.14%* 1458.10 * 5.90%*
Amean fault-huge-3 2582.29 ( 0.00%) 2556.45 ( 1.00%) 2756.65 * -6.75%* 2157.29 * 16.46%*
Amean fault-huge-4 2352.21 ( 0.00%) 2709.37 * -15.18%* 2323.89 ( 1.20%) 1888.94 * 19.69%*
Amean fault-both-1 1549.55 ( 0.00%) 1667.13 * -7.59%* 1361.50 * 12.14%* 1458.10 * 5.90%*
Amean fault-both-3 2582.29 ( 0.00%) 2556.45 ( 1.00%) 2756.65 * -6.75%* 2157.29 * 16.46%*
Amean fault-both-4 2352.21 ( 0.00%) 2709.37 * -15.18%* 2323.89 ( 1.20%) 1888.94 * 19.69%*
Stddev fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Stddev fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Stddev fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Stddev fault-huge-1 2011.48 ( 0.00%) 3765.64 ( -87.21%) 3061.45 ( -52.20%) 1758.56 ( 12.57%)
Stddev fault-huge-3 11153.49 ( 0.00%) 8339.83 ( 25.23%) 7017.28 ( 37.08%) 3976.86 ( 64.34%)
Stddev fault-huge-4 8817.67 ( 0.00%) 16241.48 ( -84.19%) 11595.28 ( -31.50%) 6631.47 ( 24.79%)
Stddev fault-both-1 2011.48 ( 0.00%) 3765.64 ( -87.21%) 3061.45 ( -52.20%) 1758.56 ( 12.57%)
Stddev fault-both-3 11153.49 ( 0.00%) 8339.83 ( 25.23%) 7017.28 ( 37.08%) 3976.86 ( 64.34%)
Stddev fault-both-4 8817.67 ( 0.00%) 16241.48 ( -84.19%) 11595.28 ( -31.50%) 6631.47 ( 24.79%)
CoeffVar fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
CoeffVar fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
CoeffVar fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
CoeffVar fault-huge-1 129.81 ( 0.00%) 225.88 ( -74.00%) 224.86 ( -73.22%) 120.61 ( 7.09%)
CoeffVar fault-huge-3 431.92 ( 0.00%) 326.23 ( 24.47%) 254.56 ( 41.06%) 184.35 ( 57.32%)
CoeffVar fault-huge-4 374.87 ( 0.00%) 599.46 ( -59.91%) 498.96 ( -33.10%) 351.07 ( 6.35%)
CoeffVar fault-both-1 129.81 ( 0.00%) 225.88 ( -74.00%) 224.86 ( -73.22%) 120.61 ( 7.09%)
CoeffVar fault-both-3 431.92 ( 0.00%) 326.23 ( 24.47%) 254.56 ( 41.06%) 184.35 ( 57.32%)
CoeffVar fault-both-4 374.87 ( 0.00%) 599.46 ( -59.91%) 498.96 ( -33.10%) 351.07 ( 6.35%)
Max fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Max fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Max fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
Max fault-huge-1 90549.00 ( 0.00%) 166062.00 ( -83.39%) 134242.00 ( -48.25%) 82424.00 ( 8.97%)
Max fault-huge-3 1229237.00 ( 0.00%) 392796.00 ( 68.05%) 508290.00 ( 58.65%) 433992.00 ( 64.69%)
Max fault-huge-4 418414.00 ( 0.00%) 1147308.00 (-174.20%) 792153.00 ( -89.32%) 433393.00 ( -3.58%)
Max fault-both-1 90549.00 ( 0.00%) 166062.00 ( -83.39%) 134242.00 ( -48.25%) 82424.00 ( 8.97%)
Max fault-both-3 1229237.00 ( 0.00%) 392796.00 ( 68.05%) 508290.00 ( 58.65%) 433992.00 ( 64.69%)
Max fault-both-4 418414.00 ( 0.00%) 1147308.00 (-174.20%) 792153.00 ( -89.32%) 433393.00 ( -3.58%)
BAmean-50 fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-50 fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-50 fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-50 fault-huge-1 1329.84 ( 0.00%) 1086.23 ( 18.32%) 765.68 ( 42.42%) 1238.41 ( 6.88%)
BAmean-50 fault-huge-3 1410.46 ( 0.00%) 1406.43 ( 0.29%) 1749.95 ( -24.07%) 1362.23 ( 3.42%)
BAmean-50 fault-huge-4 1453.01 ( 0.00%) 1373.01 ( 5.51%) 1268.61 ( 12.69%) 1157.08 ( 20.37%)
BAmean-50 fault-both-1 1329.84 ( 0.00%) 1086.23 ( 18.32%) 765.68 ( 42.42%) 1238.41 ( 6.88%)
BAmean-50 fault-both-3 1410.46 ( 0.00%) 1406.43 ( 0.29%) 1749.95 ( -24.07%) 1362.23 ( 3.42%)
BAmean-50 fault-both-4 1453.01 ( 0.00%) 1373.01 ( 5.51%) 1268.61 ( 12.69%) 1157.08 ( 20.37%)
BAmean-95 fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-95 fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-95 fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-95 fault-huge-1 1428.93 ( 0.00%) 1336.45 ( 6.47%) 1125.72 ( 21.22%) 1324.67 ( 7.30%)
BAmean-95 fault-huge-3 1881.39 ( 0.00%) 1868.23 ( 0.70%) 2257.90 ( -20.01%) 1794.46 ( 4.62%)
BAmean-95 fault-huge-4 1853.49 ( 0.00%) 2038.27 ( -9.97%) 1758.37 ( 5.13%) 1522.69 ( 17.85%)
BAmean-95 fault-both-1 1428.93 ( 0.00%) 1336.45 ( 6.47%) 1125.72 ( 21.22%) 1324.67 ( 7.30%)
BAmean-95 fault-both-3 1881.39 ( 0.00%) 1868.23 ( 0.70%) 2257.90 ( -20.01%) 1794.46 ( 4.62%)
BAmean-95 fault-both-4 1853.49 ( 0.00%) 2038.27 ( -9.97%) 1758.37 ( 5.13%) 1522.69 ( 17.85%)
BAmean-99 fault-base-1 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-99 fault-base-3 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-99 fault-base-4 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
BAmean-99 fault-huge-1 1447.04 ( 0.00%) 1394.38 ( 3.64%) 1188.40 ( 17.87%) 1359.40 ( 6.06%)
BAmean-99 fault-huge-3 2139.13 ( 0.00%) 2127.28 ( 0.55%) 2500.44 ( -16.89%) 2024.05 ( 5.38%)
BAmean-99 fault-huge-4 2051.01 ( 0.00%) 2141.53 ( -4.41%) 1959.27 ( 4.47%) 1705.47 ( 16.85%)
BAmean-99 fault-both-1 1447.04 ( 0.00%) 1394.38 ( 3.64%) 1188.40 ( 17.87%) 1359.40 ( 6.06%)
BAmean-99 fault-both-3 2139.13 ( 0.00%) 2127.28 ( 0.55%) 2500.44 ( -16.89%) 2024.05 ( 5.38%)
BAmean-99 fault-both-4 2051.01 ( 0.00%) 2141.53 ( -4.41%) 1959.27 ( 4.47%) 1705.47 ( 16.85%)

thpscale Percentage Faults Huge
thp thp thp thp
base1 base2 lru1 lru2
Percentage huge-1 100.00 ( 0.00%) 100.00 ( 0.00%) 100.00 ( 0.00%) 100.00 ( 0.00%)
Percentage huge-3 100.00 ( 0.00%) 100.00 ( 0.00%) 100.00 ( 0.00%) 100.00 ( 0.00%)
Percentage huge-4 100.00 ( 0.00%) 100.00 ( 0.00%) 100.00 ( 0.00%) 100.00 ( 0.00%)

thp thp thp thp
base1 base2 lru1 lru2
Duration User 93.79 93.26 93.61 97.02
Duration System 592.52 601.32 585.31 575.20
Duration Elapsed 1239.40 1243.79 1232.97 1229.09

thp thp thp thp
base1 base2 lru1 lru2
Ops Minor Faults 2532126.00 2377121.00 2410222.00 2414384.00
Ops Major Faults 836.00 722.00 778.00 610.00
Ops Swap Ins 676.00 644.00 656.00 760.00
Ops Swap Outs 15887.00 15705.00 11341.00 6812.00
Ops Allocation stalls 67986.00 44391.00 48791.00 70025.00
Ops Fragmentation stalls 0.00 0.00 0.00 0.00
Ops DMA allocs 0.00 0.00 0.00 0.00
Ops DMA32 allocs 0.00 0.00 0.00 0.00
Ops Normal allocs 163203689.00 154651154.00 159354937.00 165237378.00
Ops Movable allocs 0.00 0.00 0.00 0.00
Ops Direct pages scanned 832666.00 1385214.00 652686.00 499004.00
Ops Kswapd pages scanned 808301.00 3517190.00 2310658.00 615450.00
Ops Kswapd pages reclaimed 28737.00 314122.00 13761.00 21149.00
Ops Direct pages reclaimed 1542.00 118664.00 278.00 5002.00
Ops Kswapd efficiency % 3.56 8.93 0.60 3.44
Ops Kswapd velocity 652.17 2827.80 1874.06 500.74
Ops Direct efficiency % 0.19 8.57 0.04 1.00
Ops Direct velocity 671.83 1113.70 529.36 405.99
Ops Percentage direct scans 50.74 28.26 22.03 44.78
Ops Page writes by reclaim 15887.00 15705.00 11341.00 6812.00
Ops Page writes file 0.00 0.00 0.00 0.00
Ops Page writes anon 15887.00 15705.00 11341.00 6812.00
Ops Page reclaim immediate 0.00 0.00 0.00 0.00
Ops Sector Reads 79350969.00 79290528.00 79326339.00 79294800.00
Ops Sector Writes 105724641.00 105722825.00 105705814.00 105687161.00
Ops Page rescued immediate 0.00 0.00 0.00 0.00
Ops Slabs scanned 83935.00 113839.00 100286.00 78442.00
Ops Direct inode steals 56.00 44.00 86.00 31.00
Ops Kswapd inode steals 0.00 1.00 2.00 2.00
Ops Kswapd skipped wait 0.00 0.00 0.00 0.00
Ops THP fault alloc 232051.00 232036.00 232035.00 232035.00
Ops THP fault fallback 1.00 0.00 0.00 0.00
Ops THP collapse alloc 13.00 12.00 15.00 11.00
Ops THP collapse fail 0.00 0.00 0.00 0.00
Ops THP split 22665.00 52360.00 35592.00 15363.00
Ops THP split failed 0.00 0.00 0.00 0.00
Ops Compaction stalls 144127.00 120784.00 125512.00 144578.00
Ops Compaction success 8039.00 24423.00 15316.00 3672.00
Ops Compaction failures 136088.00 96361.00 110196.00 140906.00
Ops Compaction efficiency 5.58 20.22 12.20 2.54
Ops Page migrate success 4170185.00 12177428.00 7860810.00 3037053.00
Ops Page migrate failure 9476.00 9987.00 1987.00 623.00
Ops Compaction pages isolated 9551164.00 25547480.00 16290756.00 6222921.00
Ops Compaction migrate scanned 6529450.00 15982527.00 9845328.00 5711509.00
Ops Compaction free scanned 17198448.00 21663579.00 9531167.00 10790527.00
Ops Compact scan efficiency 37.97 73.78 103.30 52.93
Ops Compaction cost 4555.96 13237.59 8537.99 3310.69
Ops Kcompactd wake 51.00 88.00 48.00 20.00
Ops Kcompactd migrate scanned 127333.00 325654.00 144656.00 670374.00
Ops Kcompactd free scanned 100028.00 35658.00 12486.00 127376.00
Ops NUMA alloc hit 48379083.00 48250045.00 48278578.00 48259808.00
Ops NUMA alloc miss 68141.00 51994.00 61465.00 70881.00
Ops NUMA interleave hit 0.00 0.00 0.00 0.00
Ops NUMA alloc local 48379030.00 48250007.00 48278535.00 48259769.00
Ops NUMA base-page range updates 19832.00 4340.00 14959.00 5190.00
Ops NUMA PTE updates 2424.00 756.00 1647.00 1094.00
Ops NUMA PMD updates 34.00 7.00 26.00 8.00
Ops NUMA hint faults 2148.00 386.00 1411.00 415.00
Ops NUMA hint local faults % 1814.00 362.00 1401.00 238.00
Ops NUMA hint local percent 84.45 93.78 99.29 57.35
Ops NUMA pages migrated 5392.00 535.00 1030.00 1710.00
Ops AutoNUMA cost 10.98 1.97 7.18 2.14