On Sun, 2013-01-27 at 10:41 +0800, Alex Shi wrote:
> On 01/24/2013 11:07 PM, Alex Shi wrote:
> > On 01/24/2013 05:44 PM, Borislav Petkov wrote:
> >> On Thu, Jan 24, 2013 at 11:06:42AM +0800, Alex Shi wrote:
> >>> Since the runnable info needs 345ms to accumulate, balancing
> >>> doesn't do well for many tasks burst waking. After talking with Mike
> >>> Galbraith, we are agree to just use runnable avg in power friendly
> >>> scheduling and keep current instant load in performance scheduling for
> >>> low latency.
> >>>
> >>> So the biggest change in this version is removing runnable load avg in
> >>> balance and just using runnable data in power balance.
> >>>
> >>> The patchset bases on Linus' tree, includes 3 parts,
> >>> ** 1, bug fix and fork/wake balancing clean up. patch 1~5,
> >>> ----------------------
> >>> the first patch remove one domain level. patch 2~5 simplified fork/wake
> >>> balancing, it can increase 10+% hackbench performance on our 4 sockets
> >>> SNB EP machine.
> >>
> >> Ok, I see some benchmarking results here and there in the commit
> >> messages but since this is touching the scheduler, you probably would
> >> need to make sure it doesn't introduce performance regressions vs
> >> mainline with a comprehensive set of benchmarks.
> >>
> >
> > Thanks a lot for your comments, Borislav! :)
> >
> > For this patchset, the code will just check current policy, if it is
> > performance, the code patch will back to original performance code at
> > once. So there should no performance change on performance policy.
> >
> > I once tested the balance policy performance with benchmark
> > kbuild/hackbench/aim9/dbench/tbench on version 2, only hackbench has a
> > bit drop ~3%. others have no clear change.
> >
> >> And, AFAICR, mainline does by default the 'performance' scheme by
> >> spreading out tasks to idle cores, so have you tried comparing vanilla
> >> mainline to your patchset in the 'performance' setting so that you can
> >> make sure there are no problems there? And not only hackbench or a
> >> microbenchmark but aim9 (I saw that in a commit message somewhere) and
> >> whatever else multithreaded benchmark you can get your hands on.
> >>
> >> Also, you might want to run it on other machines too, not only SNB :-)
> >
> > Anyway I will redo the performance testing on this version again on all
> > machine. but doesn't expect something change. :)
>
> Just rerun some benchmarks: kbuild, specjbb2005, oltp, tbench, aim9,
> hackbench, fileio-cfq of sysbench, dbench, aiostress, multhreads
> loopback netperf. on my core2, nhm, wsm, snb, platforms. no clear
> performance change found.
With aim7 compute on 4 node 40 core box, I see stable throughput
improvement at tasks = nr_cores and below w. balance and powersaving.
3.8.0-performance 3.8.0-balance
3.8.0-powersaving
Tasks jobs/min jti jobs/min/task real cpu jobs/min jti
jobs/min/task real cpu jobs/min jti jobs/min/task real
cpu
1 432.86 100 432.8571 14.00 3.99 433.48 100
433.4764 13.98 3.97 433.17 100 433.1665 13.99 3.98
1 437.23 100 437.2294 13.86 3.85 436.60 100
436.5994 13.88 3.86 435.66 100 435.6578 13.91 3.90
1 434.10 100 434.0974 13.96 3.95 436.29 100
436.2851 13.89 3.89 436.29 100 436.2851 13.89 3.87
5 2400.95 99 480.1902 12.62 12.49 2554.81 98
510.9612 11.86 7.55 2487.68 98 497.5369 12.18 8.22
5 2341.58 99 468.3153 12.94 13.95 2578.72 99
515.7447 11.75 7.25 2527.11 99 505.4212 11.99 7.90
5 2350.66 99 470.1319 12.89 13.66 2600.86 99
520.1717 11.65 7.09 2508.28 98 501.6556 12.08 8.24
10 4291.78 99 429.1785 14.12 40.14 5334.51 99
533.4507 11.36 11.13 5183.92 98 518.3918 11.69 12.15
10 4334.76 99 433.4764 13.98 38.70 5311.13 99
531.1131 11.41 11.23 5215.15 99 521.5146 11.62 12.53
10 4273.62 99 427.3625 14.18 40.29 5287.96 99
528.7958 11.46 11.46 5144.31 98 514.4312 11.78 12.32
20 8487.39 94 424.3697 14.28 63.14 10594.41 99
529.7203 11.44 23.72 10575.92 99 528.7958 11.46 22.08
20 8387.54 97 419.3772 14.45 77.01 10575.92 98
528.7958 11.46 23.41 10520.83 99 526.0417 11.52 21.88
20 8713.16 95 435.6578 13.91 55.10 10659.63 99
532.9815 11.37 24.17 10539.13 99 526.9565 11.50 22.13
40 16786.70 99 419.6676 14.44 170.08 19469.88 98
486.7470 12.45 60.78 19967.05 98 499.1763 12.14 51.40
40 16728.78 99 418.2195 14.49 172.96 19627.53 98
490.6883 12.35 65.26 20386.88 98 509.6720 11.89 46.91
40 16763.49 99 419.0871 14.46 171.42 20033.06 98
500.8264 12.10 51.44 20682.59 98 517.0648 11.72 42.45
No deltas after that. There were also no deltas between patched kernel
using performance policy and virgin source.
-Mike
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