Re: [PATCH]sched: Isochronous class v2 for unprivileged soft rt scheduling

[Con Kolivas <kernel@kolivas.org>]

Jack O'Quin wrote:
> Con Kolivas <kernel@kolivas.org> writes:
> 
> 
>>Con Kolivas wrote:
>>
>>Here are my results with SCHED_ISO v2 on a pentium-M 1.7Ghz (all
>>powersaving features off):
>>
>>Increasing iso_cpu did not change the results.
>>
>>At least in my testing on my hardware, v2 is working as advertised. I
>>need results from more hardware configurations to know if priority
>>support is worth adding or not.
> 
> 
> Excellent.  Judging by the DSP Load, your machine seems to run almost
> twice as fast as my 1.5GHz Athlon (surprising).  You might want to try

Not really surprising; the 2Mb cache makes this a damn fine cpu, if not 
necessarily across the board :)

> pushing it a bit harder by running more clients (2nd parameter,
> default is 20).

Ask and ye shall receive.

> Are you getting fairly consistent results running SCHED_ISO
> repeatedly?  That worked better for me after I fixed that bug in JACK
> 0.99.47, but I think there is still more variance than with
> SCHED_FIFO.

Much more consistent, and I believe some bugs in the earlier 
implementation were probably biting.

40 clients:
SCHED_FIFO:
*********************************************
Timeout Count . . . . . . . . :(    0)
XRUN Count  . . . . . . . . . :     7
Delay Count (>spare time) . . :    20
Delay Count (>1000 usecs) . . :     0
Delay Maximum . . . . . . . . :  6739   usecs
Cycle Maximum . . . . . . . . :   746   usecs
Average DSP Load. . . . . . . :    30.4 %
Average CPU System Load . . . :     5.7 %
Average CPU User Load . . . . :    23.3 %
Average CPU Nice Load . . . . :     0.0 %
Average CPU I/O Wait Load . . :     0.0 %
Average CPU IRQ Load  . . . . :     0.6 %
Average CPU Soft-IRQ Load . . :     0.0 %
Average Interrupt Rate  . . . :  1692.0 /sec
Average Context-Switch Rate . : 20907.7 /sec
*********************************************

SCHED_ISO:
*********************************************
Timeout Count . . . . . . . . :(    0)
XRUN Count  . . . . . . . . . :    11
Delay Count (>spare time) . . :    19
Delay Count (>1000 usecs) . . :     0
Delay Maximum . . . . . . . . :  8723   usecs
Cycle Maximum . . . . . . . . :   714   usecs
Average DSP Load. . . . . . . :    31.1 %
Average CPU System Load . . . :     5.7 %
Average CPU User Load . . . . :    23.2 %
Average CPU Nice Load . . . . :     0.0 %
Average CPU I/O Wait Load . . :     0.0 %
Average CPU IRQ Load  . . . . :     0.6 %
Average CPU Soft-IRQ Load . . :     0.0 %
Average Interrupt Rate  . . . :  1685.4 /sec
Average Context-Switch Rate . : 20496.9 /sec
*********************************************

Full results and pretty pictures available here:
http://ck.kolivas.org/patches/SCHED_ISO/iso2-benchmarks/

Cheers,
Con