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

[Mike Galbraith <efault@gmx.de>]

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