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

From: Con Kolivas
Date: Wed Jan 19 2005 - 21:08:17 EST


Jack O'Quin wrote:
Con Kolivas <kernel@xxxxxxxxxxx> 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
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