Re: Scheduler benchmarks - a follow-up

From: Ed Tomlinson
Date: Mon Sep 17 2007 - 07:19:04 EST


Rob,

I gather this was with the complete -ck patchset? It would be interesting to see if just SD
performed as well. If it does, CFS needs more work. if not there are other things in -ck
that really do improve performance and should be looked into.

Thanks
Ed Tomlinson

On September 17, 2007, Rob Hussey wrote:
> Hi all,
>
> After posting some benchmarks involving cfs
> (http://lkml.org/lkml/2007/9/13/385), I got some feedback, so I
> decided to do a follow-up that'll hopefully fill in the gaps many
> people wanted to see filled.
>
> This time around I've done the benchmarks against 2.6.21, 2.6.22-ck1,
> and 2.6.23-rc6-cfs-devel (latest git as of 12 hours ago). All three
> .configs are attached. The benchmarks consist of lat_ctx and
> hackbench, both with a growing number of processes, as well as
> pipe-test. All benchmarks were also run bound to a single core.
>
> Since this time there are hundreds of lines of data, I'll post a
> reasonable amount here and attach the data files. There are graphs
> again this time, which I'll post links to as well as attach.
>
> I'll start with some selected numbers, which are preceded by the
> command used for the benchmark.
>
> for((i=2; i < 201; i++)); do lat_ctx -s 0 $i; done:
> (the left most column is the number of processes ($i))
>
> 2.6.21 2.6.22-ck1 2.6.23-rc6-cfs-devel
>
> 15 5.88 4.85 5.14
> 16 5.80 4.77 4.76
> 17 5.91 4.84 4.92
> 18 5.79 4.86 4.83
> 19 5.89 4.94 4.93
> 20 5.78 4.81 5.13
> 21 5.88 5.02 4.94
> 22 5.79 4.79 4.84
> 23 5.93 4.86 5.05
> 24 5.73 4.76 4.90
> 25 6.00 4.94 5.19
>
> for((i=1; i < 100; i++)); do hackbench $i; done:
>
> 2.6.21 2.6.22-ck1 2.6.23-rc6-cfs-devel
>
> 80 9.75 8.95 9.52
> 81 11.54 8.87 9.57
> 82 11.29 8.92 9.67
> 83 10.76 8.96 9.82
> 84 12.04 9.20 9.91
> 85 11.74 9.39 10.09
> 86 12.01 9.37 10.18
> 87 11.39 9.43 10.13
> 88 12.48 9.60 10.38
> 89 11.85 9.77 10.52
> 90 13.78 9.76 10.65
>
> pipe-test:
> (the left most column is the run #)
>
> 2.6.21 2.6.22-ck1 2.6.23-rc6-cfs-devel
>
> 1 13.84 12.59 13.01
> 2 13.90 12.57 13.00
> 3 13.84 12.62 13.06
> 4 13.87 12.61 13.04
> 5 13.82 12.62 13.03
> 6 13.86 12.60 13.02
> 7 13.85 12.61 13.02
> 8 13.88 12.45 13.04
> 9 13.83 12.46 13.03
> 10 13.88 12.46 13.03
>
> Bound to Single core:
>
> for((i=2; i < 201; i++)); do lat_ctx -s 0 $i; done:
>
> 2.6.21 2.6.22-ck1 2.6.23-rc6-cfs-devel
>
> 15 2.90 2.76 2.21
> 16 2.88 2.79 2.36
> 17 2.87 2.77 2.52
> 18 2.86 2.78 2.66
> 19 2.89 2.72 2.81
> 20 2.87 2.72 2.95
> 21 2.86 2.69 3.10
> 22 2.88 2.72 3.26
> 23 2.86 2.71 3.39
> 24 2.84 2.72 3.56
> 25 2.82 2.73 3.72
>
>
> for((i=1; i < 100; i++)); do hackbench $i; done:
>
> 2.6.21 2.6.22-ck1 2.6.23-rc6-cfs-devel
>
> 80 14.29 10.86 12.03
> 81 14.40 11.25 12.17
> 82 15.00 11.42 12.33
> 83 14.87 11.12 12.51
> 84 15.37 11.42 12.66
> 85 15.75 11.68 12.79
> 86 15.64 11.95 12.95
> 87 15.80 11.64 13.12
> 88 15.70 11.91 13.25
> 89 15.10 12.19 13.42
> 90 16.24 12.53 13.54
>
> pipe-test:
>
> 2.6.21 2.6.22-ck1 2.6.23-rc6-cfs-devel
>
> 1 9.27 8.50 8.55
> 2 9.27 8.47 8.55
> 3 9.28 8.47 8.54
> 4 9.28 8.48 8.54
> 5 9.28 8.48 8.54
> 6 9.29 8.46 8.54
> 7 9.28 8.47 8.55
> 8 9.29 8.47 8.55
> 9 9.29 8.45 8.54
> 10 9.28 8.46 8.54
>
> Links to the graphs (the .dat files are in the same directory):
> http://www.healthcarelinen.com/misc/benchmarks/lat_ctx_benchmark2.png
> http://www.healthcarelinen.com/misc/benchmarks/hackbench_benchmark2.png
> http://www.healthcarelinen.com/misc/benchmarks/pipe-test_benchmark2.png
> http://www.healthcarelinen.com/misc/benchmarks/BOUND_lat_ctx_benchmark2.png
> http://www.healthcarelinen.com/misc/benchmarks/BOUND_hackbench_benchmark2.png
> http://www.healthcarelinen.com/misc/benchmarks/BOUND_pipe-test_benchmark2.png
>
> The only analysis I'll offer is that both sd and cfs are improvements,
> and I'm glad that there is a lot of work being done in this area of
> linux development. Much respect to Con Kolivas, Ingo Molnar, and Roman
> Zippel, as well all the others who have contributed.
>
> Any feedback is welcome.
>
> Regards,
> Rob
>


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