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

[Con Kolivas <kernel@kolivas.org>]

Con Kolivas wrote:
> Jack O'Quin wrote:
>> I was misreading the x-axis.  They're actually every 20 sec.  My
>> system isn't doing that.
> 
> 
> Possibly reiserfs journal related. That has larger non-preemptible code 
> sections.
> 
>> You're really getting hammered with those periodic 6 msec delays,
>> though.  The basic audio cycle is only 1.45 msec.
> 
> 
> As you've already pointed out, though, they occur even with SCHED_FIFO 
> so I'm certain it's an artefact unrelated to cpu scheduling.

Ok to try and answer my own possibility I remounted reiserfs with the 
nolog option and tested with SCHED_ISO

*********************************************
Timeout Count . . . . . . . . :(    0)
XRUN Count  . . . . . . . . . :     0
Delay Count (>spare time) . . :     1
Delay Count (>1000 usecs) . . :     0
Delay Maximum . . . . . . . . :  6750   usecs
Cycle Maximum . . . . . . . . :   717   usecs
Average DSP Load. . . . . . . :    30.7 %
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  . . . :  1683.8 /sec
Average Context-Switch Rate . : 20015.8 /sec
*********************************************


You'll see on
http://ck.kolivas.org/patches/SCHED_ISO/iso2-benchmarks/jack_test3-iso2-40c-nolog.png

That the 20s periodic thing delay has all but gone. Just one towards the 
end (no idea what that was).

Cheers,
Con