Re: [announce] CFS-devel, performance improvements

["Rob Hussey" <robjhussey@gmail.com>]

On 9/13/07, Ingo Molnar <mingo@elte.hu> wrote:
>
> * Rob Hussey <robjhussey@gmail.com> wrote:
>
> > Well, I was going over my config myself after you asked for me to post
> > it, and I thought to do the same thing. Except, disabling sched_debug
> > caused the same error as before:
> > In file included from kernel/sched.c:794:
> > kernel/sched_fair.c: In function 'task_new_fair':
> > kernel/sched_fair.c:857: error: 'sysctl_sched_child_runs_first'
> > undeclared (first use in this function)
> > kernel/sched_fair.c:857: error: (Each undeclared identifier is
> > reported only once
> > kernel/sched_fair.c:857: error: for each function it appears in.)
> > make[1]: *** [kernel/sched.o] Error 1
> > make: *** [kernel] Error 2
> >
> > It only happens with sched_debug=y. I take it back, it wasn't my fault :)
> >
> > As for everything else, I'd be happy to.
>
> are you sure this is happening with the latest iteration of the patch
> too? (with the combo-3.patch?) You can pick it up from here:
>
>    http://people.redhat.com/mingo/cfs-scheduler/devel/sched-cfs-v2.6.23-rc6-v21-combo-3.patch
>
> I tried your config and it builds fine here.
>
>         Ingo
>

I managed to work it all out (it was my fault after all), and I've now
made the changes you suggested to my .configs for 2.6.23-rc1 and
2.6.23-rc6. I've done the benchmarks all over, including tests with
the task bound to a single core. Without further ado, the numbers I
promised:

lat_ctx -s 0 2
#  rc1	  rc6  cfs-devel
1  4.58  4.39  4.42
2  4.76  4.42  4.41
3  4.74  4.52  4.67
4  4.74  4.44  4.76
5  4.79  4.74  4.59
6  4.80  4.65  4.76
7  4.52  4.54  4.50
8  4.72  4.57  4.62
9  4.87  4.67  4.80
10 4.69  4.47  4.65

hackbench 50
#  rc1    rc6    cfs-devel
1  6.634  5.969  5.894
2  6.342  5.974  5.903
3  6.219  5.913  5.941
4  6.702  5.980  5.916
5  6.287  6.007  5.943
6  6.239  6.022  5.899
7  6.434  5.946  5.904
8  6.229  6.007  5.941
9  6.387  5.947  5.880
10 6.383  5.946  5.933

pipe-test
#  rc1   rc6   cfs-devel
1  13.39 13.16 13.20
2  13.37 13.12 13.22
3  13.19 13.17 13.26
4  13.17 13.16 13.18
5  13.16 13.22 13.23
6  13.15 13.19 13.18
7  13.18 13.42 13.21
8  13.45 13.39 13.26
9  13.40 13.40 13.28
10 13.39 13.44 13.24

Bound to single core:

lat_ctx -s 0 2
#  rc1  rc6  cfs-devel
1  3.20 2.61 2.37
2  3.20 2.60 2.40
3  3.21 2.67 2.38
4  3.19 2.66 2.34
5  3.19 2.64 2.37
6  3.22 2.67 2.36
7  3.21 3.29 2.36
8  3.22 2.61 2.44
9  3.23 2.68 2.36
10 3.22 2.60 2.37

hackbench 50
#  rc1   rc6   cfs-devel
1  7.528 7.950 7.538
2  7.649 8.026 7.548
3  7.613 8.160 7.580
4  7.550 8.054 7.558
5  7.563 8.373 7.559
6  7.617 8.152 7.550
7  7.593 7.831 7.562
8  7.602 8.311 7.588
9  7.589 8.010 7.552
10 7.682 8.059 7.556

pipe-test
#  rc1   rc6  cfs-devel
1  10.29 9.27 8.54
2  10.30 9.29 8.54
3  10.31 9.28 8.54
4  10.29 9.27 8.54
5  10.28 9.28 8.53
6  10.30 9.28 8.53
7  10.30 9.28 8.54

I've made graphs like last time:
http://www.healthcarelinen.com/misc/lat_ctx_benchmark.png
http://www.healthcarelinen.com/misc/hackbench_benchmark.png
http://www.healthcarelinen.com/misc/pipe-test_benchmark.png
http://www.healthcarelinen.com/misc/BOUND_lat_ctx_benchmark.png
http://www.healthcarelinen.com/misc/BOUND_hackbench_benchmark.png
http://www.healthcarelinen.com/misc/BOUND_pipe-test_benchmark.png

I'll also attach the graphs, as well as my .configs.

As for the data, I really can't read much into it. I think the graphs
tell the story better (if only I could understand the story). Overall
though, a definite improvement over 2.6.23-rc1.

Attachment: lat_ctx_benchmark.png
Description: PNG image

Attachment: hackbench_benchmark.png
Description: PNG image

Attachment: pipe-test_benchmark.png
Description: PNG image

Attachment: BOUND_lat_ctx_benchmark.png
Description: PNG image

Attachment: BOUND_hackbench_benchmark.png
Description: PNG image

Attachment: BOUND_pipe-test_benchmark.png
Description: PNG image

Attachment: config-2.6.23-rc1-linus.bz2
Description: BZip2 compressed data

Attachment: config-2.6.23-rc6-cfs.bz2
Description: BZip2 compressed data