Re: [patch v4 0/18] sched: simplified fork, release load avg andpower awareness scheduling

From: Mike Galbraith
Date: Mon Jan 28 2013 - 01:15:14 EST


On Mon, 2013-01-28 at 13:51 +0800, Alex Shi wrote:
> On 01/28/2013 01:17 PM, Mike Galbraith wrote:
> > On Sun, 2013-01-27 at 16:51 +0100, Mike Galbraith wrote:
> >> On Sun, 2013-01-27 at 21:25 +0800, Alex Shi wrote:
> >>> On 01/27/2013 06:35 PM, Borislav Petkov wrote:
> >>>> On Sun, Jan 27, 2013 at 05:36:25AM +0100, Mike Galbraith wrote:
> >>>>> With aim7 compute on 4 node 40 core box, I see stable throughput
> >>>>> improvement at tasks = nr_cores and below w. balance and powersaving.
> >> ...
> >>>> Ok, this is sick. How is balance and powersaving better than perf? Both
> >>>> have much more jobs per minute than perf; is that because we do pack
> >>>> much more tasks per cpu with balance and powersaving?
> >>>
> >>> Maybe it is due to the lazy balancing on balance/powersaving. You can
> >>> check the CS times in /proc/pid/status.
> >>
> >> Well, it's not wakeup path, limiting entry frequency per waker did zip
> >> squat nada to any policy throughput.
> >
> > monteverdi:/abuild/mike/:[0]# echo powersaving > /sys/devices/system/cpu/sched_policy/current_sched_policy
> > monteverdi:/abuild/mike/:[0]# massive_intr 10 60
> > 043321 00058616
> > 043313 00058616
> > 043318 00058968
> > 043317 00058968
> > 043316 00059184
> > 043319 00059192
> > 043320 00059048
> > 043314 00059048
> > 043312 00058176
> > 043315 00058184
> > monteverdi:/abuild/mike/:[0]# echo balance > /sys/devices/system/cpu/sched_policy/current_sched_policy
> > monteverdi:/abuild/mike/:[0]# massive_intr 10 60
> > 043337 00053448
> > 043333 00053456
> > 043338 00052992
> > 043331 00053448
> > 043332 00053488
> > 043335 00053496
> > 043334 00053480
> > 043329 00053288
> > 043336 00053464
> > 043330 00053496
> > monteverdi:/abuild/mike/:[0]# echo performance > /sys/devices/system/cpu/sched_policy/current_sched_policy
> > monteverdi:/abuild/mike/:[0]# massive_intr 10 60
> > 043348 00052488
> > 043344 00052488
> > 043349 00052744
> > 043343 00052504
> > 043347 00052504
> > 043352 00052888
> > 043345 00052504
> > 043351 00052496
> > 043346 00052496
> > 043350 00052304
> > monteverdi:/abuild/mike/:[0]#
>
> similar with aim7 results. Thanks, Mike!
>
> Wold you like to collect vmstat info in background?
> >
> > Zzzt. Wish I could turn turbo thingy off.
>
> Do you mean the turbo mode of cpu frequency? I remember some of machine
> can disable it in BIOS.

Yeah, I can do that in my local x3550 box. I can't fiddle with BIOS
settings on the remote NUMA box.

This can't be anything but turbo gizmo mucking up the numbers I think,
not that the numbers are invalid or anything, better numbers are better
numbers no matter where/how they come about ;-)

The massive_intr load is dirt simple sleep/spin with bean counting. It
sleeps 1ms spins 8ms. Change that to sleep 8ms, grind away for 1ms...

monteverdi:/abuild/mike/:[0]# ./massive_intr 10 60
045150 00006484
045157 00006427
045156 00006401
045152 00006428
045155 00006372
045154 00006370
045158 00006453
045149 00006372
045151 00006371
045153 00006371
monteverdi:/abuild/mike/:[0]# echo balance > /sys/devices/system/cpu/sched_policy/current_sched_policy
monteverdi:/abuild/mike/:[0]# ./massive_intr 10 60
045170 00006380
045172 00006374
045169 00006376
045175 00006376
045171 00006334
045176 00006380
045168 00006374
045174 00006334
045177 00006375
045173 00006376
monteverdi:/abuild/mike/:[0]# echo performance > /sys/devices/system/cpu/sched_policy/current_sched_policy
monteverdi:/abuild/mike/:[0]# ./massive_intr 10 60
045198 00006408
045191 00006408
045197 00006408
045192 00006411
045194 00006409
045196 00006409
045195 00006336
045189 00006336
045193 00006411
045190 00006410

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