[LAU] phasex-0.12.0-beta4

[William Weston]

On Tue, 22 Sep 2009, Nedko Arnaudov wrote:

> Nedko Arnaudov <nedko at arnaudov.name> writes:
>
>> I get "wrong" sound. JACK reports no xruns.
>>
>> http://nedko.arnaudov.name/tmp/phasex.wav

Yup.  I know the sound well, and hopefully now it's nothing more 
than a memory.  The broken ringbuffer read has been fixed, and now 
uses two buffer periods instead of one.  0.12.0-pre1 should treat 
you right.

> Some more info...
> Switching tabs in my window manager (ion3) causes artefacts in phasex
> sound. I run jack2 in realtime mode, dsp load is about 15%. I run
> a 2.6.23.1-rt11 kernel. I run the opensource radeon driver. My audiocard
> and rtc IRQ threads run at higher priority than JACK (82 and 98). JACK
> runs at priority 80.

0.12.0-pre1 now defaults to SCHED_RR and should behave a little 
better.  I can run muse, hydrogen, and six instances of phasex on my 
Turion laptop, clock it down to 1.6GHz, fire off a couple mprime 
stress tester threads, and switch tabs to my heart's content without 
hearing the "wrong" sound now.  This has been tested both with and 
without the opensource radeon drm.  If you can, enable BackingStore 
in the "Device" section of your xorg.conf so the knobs don't have to 
be redrawn every tinme you switch tabs.

The clocks in my Turion really don't like the 2.6.23-rt or 
2.6.24-rt kernels, so all of this has been tested on 2.6.31-rt11. 
This is the first kernel on this particular laptop that can give me 
drm, exa acceleration, and backing store at the same time.

> # ps -eLo rtprio,pid,spid,class,args |sort -rn|head -n 20
>    99     4     4 FF  [posix_cpu_timer]
>    99     3     3 FF  [migration/0]
>    98   845   845 FF  [IRQ-8]
>    97     5     5 FF  [softirq-high/0]
>    82  1232  1232 FF  [IRQ-20]
>    80 12779 22340 RR  /usr/bin/jackdbus auto
>    80 12779 22338 RR  /usr/bin/jackdbus auto
>    80 12779 22337 RR  /usr/bin/jackdbus auto
>    77 22421 22424 FF  phasex-01
>    75 22421 22427 RR  phasex-01
>    75 22342 22355 RR  /usr/bin/a2jmidid dbus
>    50     9     9 FF  [softirq-block/0]
>    50   989   989 FF  [IRQ-17]
>    50   921   921 FF  [IRQ-16]
>    50     8     8 FF  [softirq-net-rx/]
>    50   854   854 FF  [IRQ-15]
>    50   851   851 FF  [IRQ-14]
>    50    80    80 FF  [IRQ-9]
>    50     7     7 FF  [softirq-net-tx/]
>    50     6     6 FF  [softirq-timer/0]
>
> -- 
> Nedko Arnaudov <GnuPG KeyID: DE1716B0>
>

It's been suggested in the past to put the softirq-high threads at a 
high priority (just under the rtc, like you have done), but I get 
xruns whenever I put it above JACK.   What kind of audio hardware 
and clock hardware do you have?  Just curious.

Give 0.12.0-pre1 a spin and let me know how it goes.

http://sysex.net/phasex


Cheers,
--ww