Re: [RFC PATCH v2 0/2] sched/fair: Choose the CPU where short task is running during wake up

From: Chen Yu
Date: Tue Nov 29 2022 - 23:03:48 EST


On 2022-11-22 at 16:01:42 +0530, K Prateek Nayak wrote:
> Hello Chenyu,
>
> I've tested v2 series on an dual socket Zen3 system (2 x 64C/128T) and
> the results are largely positive.
>
Thank you Prateek, and sorry for late response.
> tl;dr
>
> o Hackbench results are mostly similar with tip.
> o schbench sees improvements to tail latency when the system is
> loaded in NPS1 case but I do see one small regression for
> 128 workers in NPS4 mode.
> o tbench sees small gains in NPS2 and NPS4 mode
> o Stream and Spec-JBB results remain same as the tip.
> o ycsb-mongodb sees small gains in NPS2 and NPS4 mode.
> o unixbench results see small to moderate gains overall.
>
> I'll leave the detailed results below:
>
> Following are the results from running standard benchmarks on a
> dual socket Zen3 (2 x 64C/128T) machine configured in different
> NPS modes.
>
> NPS Modes are used to logically divide single socket into
> multiple NUMA region.
> Following is the NUMA configuration for each NPS mode on the system:
>
> NPS1: Each socket is a NUMA node.
> Total 2 NUMA nodes in the dual socket machine.
>
> Node 0: 0-63, 128-191
> Node 1: 64-127, 192-255
>
> NPS2: Each socket is further logically divided into 2 NUMA regions.
> Total 4 NUMA nodes exist over 2 socket.
>
> Node 0: 0-31, 128-159
> Node 1: 32-63, 160-191
> Node 2: 64-95, 192-223
> Node 3: 96-127, 223-255
>
> NPS4: Each socket is logically divided into 4 NUMA regions.
> Total 8 NUMA nodes exist over 2 socket.
>
> Node 0: 0-15, 128-143
> Node 1: 16-31, 144-159
> Node 2: 32-47, 160-175
> Node 3: 48-63, 176-191
> Node 4: 64-79, 192-207
> Node 5: 80-95, 208-223
> Node 6: 96-111, 223-231
> Node 7: 112-127, 232-255
>
> Benchmark Results:
>
> Kernel versions:
> - tip: 5.19.0 tip sched/core
> - sis_short: 5.19.0 tip sched/core + this series
>
> When we started testing, the tip was at:
> commit fdf756f71271 ("sched: Fix more TASK_state comparisons")
>
> ~~~~~~~~~~~~~
> ~ hackbench ~
> ~~~~~~~~~~~~~
>
> o NPS1
>
> Test: tip sis_short
> 1-groups: 4.06 (0.00 pct) 4.02 (0.98 pct)
> 2-groups: 4.76 (0.00 pct) 4.71 (1.05 pct)
> 4-groups: 5.22 (0.00 pct) 5.07 (2.87 pct)
> 8-groups: 5.35 (0.00 pct) 5.31 (0.74 pct)
> 16-groups: 7.21 (0.00 pct) 7.22 (-0.13 pct)
>
> o NPS2
>
> Test: tip sis_short
> 1-groups: 4.09 (0.00 pct) 4.05 (0.97 pct)
> 2-groups: 4.70 (0.00 pct) 4.69 (0.21 pct)
> 4-groups: 5.05 (0.00 pct) 4.95 (1.98 pct)
> 8-groups: 5.35 (0.00 pct) 5.27 (1.49 pct)
> 16-groups: 6.37 (0.00 pct) 6.60 (-3.61 pct)
>
> o NPS4
>
> Test: tip sis_short
> 1-groups: 4.07 (0.00 pct) 4.13 (-1.47 pct)
> 2-groups: 4.65 (0.00 pct) 4.71 (-1.29 pct)
> 4-groups: 5.13 (0.00 pct) 5.05 (1.55 pct)
> 8-groups: 5.47 (0.00 pct) 5.44 (0.54 pct)
> 16-groups: 6.82 (0.00 pct) 6.72 (1.46 pct)
>
> ~~~~~~~~~~~~
> ~ schbench ~
> ~~~~~~~~~~~~
>
> o NPS1
>
> #workers: tip sis_short
> 1: 33.00 (0.00 pct) 34.00 (-3.03 pct)
> 2: 35.00 (0.00 pct) 36.00 (-2.85 pct)
> 4: 39.00 (0.00 pct) 40.00 (-2.56 pct)
> 8: 49.00 (0.00 pct) 47.00 (4.08 pct)
> 16: 63.00 (0.00 pct) 64.00 (-1.58 pct)
> 32: 109.00 (0.00 pct) 106.00 (2.75 pct)
> 64: 208.00 (0.00 pct) 214.00 (-2.88 pct)
> 128: 559.00 (0.00 pct) 497.00 (11.09 pct)
> 256: 45888.00 (0.00 pct) 47424.00 (-3.34 pct)
> 512: 80000.00 (0.00 pct) 77952.00 (2.56 pct)
>
> o NPS2
>
> #workers: tip sis_short
> 1: 30.00 (0.00 pct) 31.00 (-3.33 pct)
> 2: 37.00 (0.00 pct) 36.00 (2.70 pct)
> 4: 39.00 (0.00 pct) 40.00 (-2.56 pct)
> 8: 51.00 (0.00 pct) 50.00 (1.96 pct)
> 16: 67.00 (0.00 pct) 67.00 (0.00 pct)
> 32: 117.00 (0.00 pct) 114.00 (2.56 pct)
> 64: 216.00 (0.00 pct) 214.00 (0.92 pct)
> 128: 529.00 (0.00 pct) 597.00 (-12.85 pct) *
> 128: 388.00 (0.00 pct) 382.00 (1.54 pct) [Verification Run]
> 256: 47040.00 (0.00 pct) 47424.00 (-0.81 pct)
> 512: 84864.00 (0.00 pct) 81792.00 (3.61 pct)
>
> o NPS4
>
> #workers: tip sis_short
> 1: 23.00 (0.00 pct) 33.00 (-43.47 pct)
> 2: 28.00 (0.00 pct) 27.00 (3.57 pct)
> 4: 41.00 (0.00 pct) 37.00 (9.75 pct)
> 8: 60.00 (0.00 pct) 56.00 (6.66 pct)
> 16: 71.00 (0.00 pct) 71.00 (0.00 pct)
> 32: 117.00 (0.00 pct) 114.00 (2.56 pct)
> 64: 227.00 (0.00 pct) 218.00 (3.96 pct)
> 128: 545.00 (0.00 pct) 747.00 (-37.06 pct) *
> 128: 383.00 (0.00 pct) 412.00 (-7.85 pct) [Verification Run]
> 256: 45632.00 (0.00 pct) 47296.00 (-3.64 pct)
> 512: 81024.00 (0.00 pct) 78720.00 (2.84 pct)
>
> Note: For lower worker count, schbench can show run to
> run variation depending on external factors. Regression
> for lower worker count can be ignored. The results are
> included to spot any large blow up in the tail latency
> for larger worker count.
>
> ~~~~~~~~~~
> ~ tbench ~
> ~~~~~~~~~~
>
> o NPS1
>
> Clients: tip sis_short
> 1 578.37 (0.00 pct) 568.72 (-1.66 pct)
> 2 1062.09 (0.00 pct) 1055.45 (-0.62 pct)
> 4 1800.62 (0.00 pct) 1833.37 (1.81 pct)
> 8 3211.02 (0.00 pct) 3124.95 (-2.68 pct)
> 16 4848.92 (0.00 pct) 4823.27 (-0.52 pct)
> 32 9091.36 (0.00 pct) 9301.80 (2.31 pct)
> 64 15454.01 (0.00 pct) 14639.52 (-5.27 pct) *
> 64 14890.79 (0.00 pct) 14314.95 (-3.86 pct) [Verification Run]
> 128 3511.33 (0.00 pct) 2740.46 (-21.95 pct) *
> 128 19750.19 (0.00 pct) 20006.42 (1.29 pct) [Verification Run]
> 256 50019.32 (0.00 pct) 50384.18 (0.72 pct)
> 512 44317.68 (0.00 pct) 44155.90 (-0.36 pct)
> 1024 41200.85 (0.00 pct) 41242.49 (0.10 pct)
>
> o NPS2
>
> Clients: tip sis_short
> 1 576.05 (0.00 pct) 578.08 (0.35 pct)
> 2 1037.68 (0.00 pct) 1098.68 (5.87 pct)
> 4 1818.13 (0.00 pct) 1838.79 (1.13 pct)
> 8 3004.16 (0.00 pct) 3071.73 (2.24 pct)
> 16 4520.11 (0.00 pct) 4820.67 (6.64 pct)
> 32 8624.23 (0.00 pct) 9264.14 (7.41 pct)
> 64 14886.75 (0.00 pct) 14976.91 (0.60 pct)
> 128 20602.00 (0.00 pct) 20247.46 (-1.72 pct)
> 256 45566.83 (0.00 pct) 48786.00 (7.06 pct)
> 512 42717.49 (0.00 pct) 44678.97 (4.59 pct)
> 1024 40936.61 (0.00 pct) 40866.32 (-0.17 pct)
>
> o NPS4
>
> Clients: tip sis_short
> 1 576.36 (0.00 pct) 588.43 (2.09 pct)
> 2 1044.26 (0.00 pct) 1074.47 (2.89 pct)
> 4 1839.77 (0.00 pct) 1852.10 (0.67 pct)
> 8 3043.53 (0.00 pct) 3235.32 (6.30 pct)
> 16 5207.54 (0.00 pct) 4804.41 (-7.74 pct) *
> 16 4620.29 (0.00 pct) 4714.69 (2.04 pct) [Verification Run]
> 32 9263.86 (0.00 pct) 8238.55 (-11.06 pct) *
> 32 9263.86 (0.00 pct) 9443.77 (1.94 pct) [Verification Run]
> 64 14959.66 (0.00 pct) 15321.44 (2.41 pct)
> 128 20698.65 (0.00 pct) 16806.27 (-18.80 pct) *
> 128 20698.65 (0.00 pct) 20978.42 (1.35 pct) [Verification Run]
> 256 46666.21 (0.00 pct) 49787.15 (6.68 pct)
> 512 41532.80 (0.00 pct) 44738.18 (7.71 pct)
> 1024 39459.49 (0.00 pct) 41473.96 (5.10 pct)
>
> Note: On the tested kernel, with 128 clients, tbench can
> run into a bottleneck during C2 exit. More details can be
> found at:
> https://lore.kernel.org/lkml/20220921063638.2489-1-kprateek.nayak@xxxxxxx/
> This issue has been fixed in v6.0 but was not part of the
> tip kernel when I started testing. This data point has
> been rerun with C2 disabled to get representative results.
This reminds me that, previously I tested with Cstates > C1 disabled, and
with turbo disabled, so as to mitigate possible deviation. May I know if
all C-states and turbo are enabled in your test besides tbench?
>
> ~~~~~~~~~~
> ~ stream ~
> ~~~~~~~~~~
>
> o NPS1
>
> - 10 Runs:
>
> Test: tip sis_short
> Copy: 328419.14 (0.00 pct) 336740.00 (2.53 pct)
> Scale: 206071.21 (0.00 pct) 212682.17 (3.20 pct)
> Add: 235271.48 (0.00 pct) 244104.35 (3.75 pct)
> Triad: 253175.80 (0.00 pct) 251776.26 (-0.55 pct)
>
> - 100 Runs:
>
> Test: tip sis_short
> Copy: 328209.61 (0.00 pct) 340132.12 (3.63 pct)
> Scale: 216310.13 (0.00 pct) 218811.70 (1.15 pct)
> Add: 244417.83 (0.00 pct) 246349.22 (0.79 pct)
> Triad: 237508.83 (0.00 pct) 260160.20 (9.53 pct)
>
> o NPS2
>
> - 10 Runs:
>
> Test: tip sis_short
> Copy: 336503.88 (0.00 pct) 319171.80 (-5.15 pct)
> Scale: 218035.23 (0.00 pct) 219061.13 (0.47 pct)
> Add: 257677.42 (0.00 pct) 256776.22 (-0.34 pct)
> Triad: 268872.37 (0.00 pct) 263751.14 (-1.90 pct)
>
> - 100 Runs:
>
> Test: tip sis_short
> Copy: 332304.34 (0.00 pct) 320547.46 (-3.53 pct)
> Scale: 223421.60 (0.00 pct) 220418.63 (-1.34 pct)
> Add: 252363.56 (0.00 pct) 254553.30 (0.86 pct)
> Triad: 266687.56 (0.00 pct) 260009.00 (-2.50 pct)
>
> o NPS4
>
> - 10 Runs:
>
> Test: tip sis_short
> Copy: 353515.62 (0.00 pct) 338973.78 (-4.11 pct)
> Scale: 228854.37 (0.00 pct) 230319.08 (0.64 pct)
> Add: 254942.12 (0.00 pct) 247794.21 (-2.80 pct)
> Triad: 270521.87 (0.00 pct) 261432.32 (-3.36 pct)
>
> - 100 Runs:
>
> Test: tip sis_short
> Copy: 374520.81 (0.00 pct) 363272.21 (-3.00 pct)
> Scale: 246280.23 (0.00 pct) 241457.83 (-1.95 pct)
> Add: 262772.72 (0.00 pct) 261924.44 (-0.32 pct)
> Triad: 283740.92 (0.00 pct) 274791.15 (-3.15 pct)
>
> ~~~~~~~~~~~~~~~~~
> ~ Spec-JBB NPS1 ~
> ~~~~~~~~~~~~~~~~~
>
> --------------------------------------------------
> | Throughput | tip | sis_short |
> --------------------------------------------------
> | Max-jOPS | 100% | 98.84% |
> | Critical-jOPS | 100% | 100.31% |
> --------------------------------------------------
>
> ~~~~~~~~~~~~~~~~
> ~ ycsb-mongodb ~
> ~~~~~~~~~~~~~~~~
>
> o NPS1
>
> tip: 131696.33 (var: 2.03%)
> sis_short: 130844.67 (var: 2.55%) (-0.64%)
>
> o NPS2:
>
> tip: 129895.33 (var: 2.34%)
> sis_short: 133104.33 (var: 1.65%) (+2.647%)
>
> o NPS4:
>
> tip: 131165.00 (var: 1.06%)
> sis_short: 138180.67 (var: 0.83%) (+5.34%)
>
> ~~~~~~~~~~~~~
> ~ unixbench ~
> ~~~~~~~~~~~~~
>
> -> unixbench-dhry2reg
>
> o NPS1
>
> kernel: tip sis_short
> Min unixbench-dhry2reg-1 48876615.50 ( 0.00%) 48489507.40 ( -0.79%)
> Min unixbench-dhry2reg-512 6260344658.90 ( 0.00%) 6253084311.60 ( -0.12%)
> Hmean unixbench-dhry2reg-1 49299721.81 ( 0.00%) 49014780.04 ( -0.58%)
> Hmean unixbench-dhry2reg-512 6267459427.19 ( 0.00%) 6261978461.64 ( -0.09%)
> CoeffVar unixbench-dhry2reg-1 0.90 ( 0.00%) 0.98 ( -9.38%)
> CoeffVar unixbench-dhry2reg-512 0.10 ( 0.00%) 0.17 ( -61.99%)
> Max unixbench-dhry2reg-1 49758806.60 ( 0.00%) 49428847.90 ( -0.66%)
> Max unixbench-dhry2reg-512 6273024869.70 ( 0.00%) 6273555460.00 ( 0.01%)
>
> o NPS2
>
> kernel: tip sis_short
> Min unixbench-dhry2reg-1 48828251.70 ( 0.00%) 48591509.40 ( -0.48%)
> Min unixbench-dhry2reg-512 6244987739.10 ( 0.00%) 6254966248.00 ( 0.16%)
> Hmean unixbench-dhry2reg-1 48869882.65 ( 0.00%) 49230596.10 ( 0.74%)
> Hmean unixbench-dhry2reg-512 6261073948.84 ( 0.00%) 6260685008.60 ( -0.01%)
> CoeffVar unixbench-dhry2reg-1 0.08 ( 0.00%) 1.20 (-1347.66%)
> CoeffVar unixbench-dhry2reg-512 0.23 ( 0.00%) 0.09 ( 59.12%)
> Max unixbench-dhry2reg-1 48909163.40 ( 0.00%) 49752650.10 ( 1.72%)
> Max unixbench-dhry2reg-512 6271411453.90 ( 0.00%) 6266517108.00 ( -0.08%)
>
> o NPS4
>
> kernel: tip sis_short
> Min unixbench-dhry2reg-1 48523981.30 ( 0.00%) 48728886.20 ( 0.42%)
> Min unixbench-dhry2reg-512 6253738837.10 ( 0.00%) 6260870171.70 ( 0.11%)
> Hmean unixbench-dhry2reg-1 48781044.09 ( 0.00%) 48969711.29 ( 0.39%)
> Hmean unixbench-dhry2reg-512 6264428474.90 ( 0.00%) 6277327761.28 ( 0.21%)
> CoeffVar unixbench-dhry2reg-1 0.46 ( 0.00%) 0.43 ( 6.91%)
> CoeffVar unixbench-dhry2reg-512 0.17 ( 0.00%) 0.29 ( -70.82%)
> Max unixbench-dhry2reg-1 48925665.20 ( 0.00%) 49091708.50 ( 0.34%)
> Max unixbench-dhry2reg-512 6274958506.80 ( 0.00%) 6296828879.20 ( 0.35%)
>
> -> unixbench-syscall
>
> o NPS1
>
> kernel: tip sis_short
> Min unixbench-syscall-1 2975654.80 ( 0.00%) 2971008.50 ( 0.16%)
> Min unixbench-syscall-512 7840226.50 ( 0.00%) 6586485.10 ( 15.99%)
> Amean unixbench-syscall-1 2976326.47 ( 0.00%) 2971920.50 * 0.15%*
> Amean unixbench-syscall-512 7850493.90 ( 0.00%) 6597210.63 * 15.96%*
> CoeffVar unixbench-syscall-1 0.03 ( 0.00%) 0.03 ( -14.26%)
> CoeffVar unixbench-syscall-512 0.13 ( 0.00%) 0.27 (-103.14%)
> Max unixbench-syscall-1 2977279.70 ( 0.00%) 2972935.80 ( 0.15%)
> Max unixbench-syscall-512 7860838.90 ( 0.00%) 6617515.40 ( 15.82%)
>
> o NPS2
>
> kernel: tip sis_short
> Min unixbench-syscall-1 2969863.60 ( 0.00%) 2974771.70 ( -0.17%)
> Min unixbench-syscall-512 8053157.60 ( 0.00%) 7411223.90 ( 7.97%)
> Amean unixbench-syscall-1 2970462.30 ( 0.00%) 2975278.63 * -0.16%*
> Amean unixbench-syscall-512 8061454.50 ( 0.00%) 7437679.30 * 7.74%*
> CoeffVar unixbench-syscall-1 0.02 ( 0.00%) 0.02 ( -17.72%)
> CoeffVar unixbench-syscall-512 0.12 ( 0.00%) 0.34 (-179.38%)
> Max unixbench-syscall-1 2970859.30 ( 0.00%) 2975972.90 ( -0.17%)
> Max unixbench-syscall-512 8072312.30 ( 0.00%) 7461732.50 ( 7.56%)
>
> o NPS4
>
> kernel: tip sis_short
> Min unixbench-syscall-1 2971799.80 ( 0.00%) 2974601.20 ( -0.09%)
> Min unixbench-syscall-512 7824196.90 ( 0.00%) 8242480.10 ( -5.35%)
> Amean unixbench-syscall-1 2973045.43 ( 0.00%) 2974739.93 * -0.06%*
> Amean unixbench-syscall-512 7826302.17 ( 0.00%) 8261295.03 * -5.56%*
> CoeffVar unixbench-syscall-1 0.04 ( 0.00%) 0.00 ( 86.39%)
> CoeffVar unixbench-syscall-512 0.03 ( 0.00%) 0.37 (-1376.49%)
> Max unixbench-syscall-1 2973786.50 ( 0.00%) 2974895.30 ( -0.04%)
> Max unixbench-syscall-512 7828115.90 ( 0.00%) 8296830.40 ( -5.99%)
>
>
> -> unixbench-pipe
>
> o NPS1
>
> kernel: tip sis_short
> Min unixbench-pipe-1 2894765.30 ( 0.00%) 2904821.00 ( 0.35%)
> Min unixbench-pipe-512 329818573.50 ( 0.00%) 329565756.00 ( -0.08%)
> Hmean unixbench-pipe-1 2898803.38 ( 0.00%) 2911189.71 * 0.43%*
> Hmean unixbench-pipe-512 330226401.69 ( 0.00%) 330389884.94 ( 0.05%)
> CoeffVar unixbench-pipe-1 0.14 ( 0.00%) 0.22 ( -62.25%)
> CoeffVar unixbench-pipe-512 0.11 ( 0.00%) 0.24 (-126.10%)
> Max unixbench-pipe-1 2902691.20 ( 0.00%) 2917740.00 ( 0.52%)
> Max unixbench-pipe-512 330440132.10 ( 0.00%) 331162497.90 ( 0.22%)
>
> o NPS2
>
> kernel: tip sis_short
> Min unixbench-pipe-1 2895327.90 ( 0.00%) 2905421.90 ( 0.35%)
> Min unixbench-pipe-512 328350065.60 ( 0.00%) 330137916.90 ( 0.54%)
> Hmean unixbench-pipe-1 2899129.86 ( 0.00%) 2910562.69 * 0.39%*
> Hmean unixbench-pipe-512 329436096.80 ( 0.00%) 330509036.17 ( 0.33%)
> CoeffVar unixbench-pipe-1 0.12 ( 0.00%) 0.20 ( -70.84%)
> CoeffVar unixbench-pipe-512 0.30 ( 0.00%) 0.10 ( 65.00%)
> Max unixbench-pipe-1 2901619.40 ( 0.00%) 2916758.50 ( 0.52%)
> Max unixbench-pipe-512 330239044.10 ( 0.00%) 330814020.50 ( 0.17%)
>
> o NPS4
>
> kernel: tip sis_short
> Min unixbench-pipe-1 2901525.60 ( 0.00%) 2909864.00 ( 0.29%)
> Min unixbench-pipe-512 330265873.90 ( 0.00%) 330543034.40 ( 0.08%)
> Hmean unixbench-pipe-1 2906184.70 ( 0.00%) 2912725.52 * 0.23%*
> Hmean unixbench-pipe-512 330854683.27 ( 0.00%) 331540275.79 ( 0.21%)
> CoeffVar unixbench-pipe-1 0.14 ( 0.00%) 0.09 ( 39.44%)
> CoeffVar unixbench-pipe-512 0.16 ( 0.00%) 0.27 ( -73.84%)
> Max unixbench-pipe-1 2909154.50 ( 0.00%) 2914249.80 ( 0.18%)
> Max unixbench-pipe-512 331245477.30 ( 0.00%) 332305755.00 ( 0.32%)
>
> -> unixbench-spawn
>
> o NPS1
>
> kernel: tip sis_short
> Min unixbench-spawn-1 6536.50 ( 0.00%) 6458.00 ( -1.20%)
> Min unixbench-spawn-512 72571.40 ( 0.00%) 91525.90 ( 26.12%)
> Hmean unixbench-spawn-1 6811.16 ( 0.00%) 6510.74 ( -4.41%)
> Hmean unixbench-spawn-512 72801.77 ( 0.00%) 91829.95 * 26.14%*
> CoeffVar unixbench-spawn-1 3.69 ( 0.00%) 1.00 ( 72.93%)
> CoeffVar unixbench-spawn-512 0.27 ( 0.00%) 0.41 ( -50.84%)
> Max unixbench-spawn-1 7021.00 ( 0.00%) 6583.60 ( -6.23%)
> Max unixbench-spawn-512 72927.00 ( 0.00%) 92257.50 ( 26.51%)
>
> o NPS2
>
> kernel: tip sis_short
> Min unixbench-spawn-1 7042.20 ( 0.00%) 7411.00 ( 5.24%)
> Min unixbench-spawn-512 85571.60 ( 0.00%) 89549.50 ( 4.65%)
> Hmean unixbench-spawn-1 7199.01 ( 0.00%) 7553.53 * 4.92%*
> Hmean unixbench-spawn-512 85717.77 ( 0.00%) 89751.68 * 4.71%*
> CoeffVar unixbench-spawn-1 3.50 ( 0.00%) 1.68 ( 51.98%)
> CoeffVar unixbench-spawn-512 0.20 ( 0.00%) 0.28 ( -36.60%)
> Max unixbench-spawn-1 7495.00 ( 0.00%) 7650.40 ( 2.07%)
> Max unixbench-spawn-512 85909.20 ( 0.00%) 90028.30 ( 4.79%)
>
> o NPS4
>
> kernel: tip sis_short
> Min unixbench-spawn-1 7521.90 ( 0.00%) 8404.10 ( 11.73%)
> Min unixbench-spawn-512 84245.70 ( 0.00%) 91260.20 ( 8.33%)
> Hmean unixbench-spawn-1 7659.12 ( 0.00%) 8526.01 * 11.32%*
> Hmean unixbench-spawn-512 84908.77 ( 0.00%) 91365.07 * 7.60%*
> CoeffVar unixbench-spawn-1 1.92 ( 0.00%) 2.06 ( -7.21%)
> CoeffVar unixbench-spawn-512 0.76 ( 0.00%) 0.10 ( 86.60%)
> Max unixbench-spawn-1 7815.40 ( 0.00%) 8729.60 ( 11.70%)
> Max unixbench-spawn-512 85532.90 ( 0.00%) 91437.30 ( 6.90%)
>
> -> unixbench-execl
>
> o NPS1
>
> kernel: tip sis_short
> Min unixbench-execl-1 5421.50 ( 0.00%) 5466.40 ( 0.83%)
> Min unixbench-execl-512 11213.50 ( 0.00%) 11720.30 ( 4.52%)
> Hmean unixbench-execl-1 5443.75 ( 0.00%) 5468.53 ( 0.46%)
> Hmean unixbench-execl-512 11311.94 ( 0.00%) 11809.97 * 4.40%*
> CoeffVar unixbench-execl-1 0.38 ( 0.00%) 0.04 ( 89.57%)
> CoeffVar unixbench-execl-512 1.03 ( 0.00%) 0.74 ( 27.60%)
> Max unixbench-execl-1 5461.90 ( 0.00%) 5470.70 ( 0.16%)
> Max unixbench-execl-512 11440.40 ( 0.00%) 11895.60 ( 3.98%)
>
> o NPS2
>
> kernel: tip sis_short
> Min unixbench-execl-1 5089.10 ( 0.00%) 5119.50 ( 0.60%)
> Min unixbench-execl-512 11772.70 ( 0.00%) 11591.40 ( -1.54%)
> Hmean unixbench-execl-1 5321.65 ( 0.00%) 5251.49 ( -1.32%)
> Hmean unixbench-execl-512 12201.73 ( 0.00%) 11665.67 ( -4.39%)
> CoeffVar unixbench-execl-1 3.87 ( 0.00%) 2.33 ( 39.91%)
> CoeffVar unixbench-execl-512 6.23 ( 0.00%) 1.04 ( 83.38%)
> Max unixbench-execl-1 5453.90 ( 0.00%) 5359.00 ( -1.74%)
> Max unixbench-execl-512 13111.60 ( 0.00%) 11805.80 ( -9.96%)
>
> o NPS4
>
> kernel: tip sis_short
> Min unixbench-execl-1 5099.40 ( 0.00%) 5352.70 ( 4.97%)
> Min unixbench-execl-512 11692.80 ( 0.00%) 13368.20 ( 14.33%)
> Hmean unixbench-execl-1 5136.86 ( 0.00%) 5404.31 * 5.21%*
> Hmean unixbench-execl-512 12053.71 ( 0.00%) 14018.53 * 16.30%*
> CoeffVar unixbench-execl-1 1.05 ( 0.00%) 0.84 ( 20.12%)
> CoeffVar unixbench-execl-512 3.85 ( 0.00%) 5.29 ( -37.45%)
> Max unixbench-execl-1 5198.70 ( 0.00%) 5434.90 ( 4.54%)
> Max unixbench-execl-512 12585.70 ( 0.00%) 14839.80 ( 17.91%)
>
>
> Except for schbench with 128 workers in NPS4 mode, I do not
> see any large regressions for the above workloads and I do
> see small to moderate gains overall for most workload, even
> the larger ones. I'll try to get data for more workload but
> overall the idea seems promising. I'll also get some numbers
> with the changes Peter suggested on Patch 1.
I spent sometime to dig into the issue which motivates me to propose this
solution. And it was found that this issue could not be easily solved
directly because there seems to be an inevitable race condition window, with the
increasing of CPU number, this race condition is exposed easlier. So
current patch is an indirect solution to avoid that, I'll send the detail
in v3.
>
> If there is any specific workload you would like me to run
> on the test machine, please do let me know.
Thanks for always helping us to test the patch, I'll send v3 once I get the
result and we can discuss on that then.

thanks,
Chenyu