Re: [Jackit-devel] Re: [linux-audio-dev] Re: [Jackit-devel] 2.4.20 + lowlat +preempt + alsa + jack = dead computer

6 Dec 2002

...
    To add one more datapoint to the thread and
(apparently good news): I'm
 testing 2.4.20 (final) + lowlat + preempt + acpi + alsa + jack and the
 computer seems to be chugging along nicely. This is with today's alsa. A
 slighly older alsa did lock the computer after 5 or so minutes of jack
 activity but I managed to reboot it with the sysrq magic key. With the
 newest alsa I got jack + freqtweak + ams (with the demo patch) running
 for 50 minutes until for some reason jack died due to a watchdog
 interrupt. Not bad.  
 Where are the lowlat and preempt patches for 2.4.20?   
 Not on the net at this point. I have been hand tweaking the originals to
 patch cleanly (trying to fix the failing chunks). I can email them to
 you, use at your own risk :-)

 BTW, results in my current tests are inconclusive, a couple of times I
 managed to freeze the machine soon after I started just jackd and
 qjackconnect. I'm currently trying to see if I can stat the stuff from
 the text console so that I can try to catch some register dumps through
 the sysrq magic key... 
I don't have the time now to analyze the results but it would seem the
problem is freqtweak in combination with jackd. When the system freezes
after starting stuff from a text console, <alt>sysrq-p prints
information about the current registers and the printout of repeated
dumps only shows the jackd and freqtweak processes over and over again.

Somehow they must be deadlocking. 

I'm hoping that typing all those numbers and parsing through ksymoops
will show us exactly where things are hanging. So much fun. 

-- Fernando

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Re: [Jackit-devel] Re: [linux-audio-dev] Re: [Jackit-devel] 2.4.20 + lowlat +preempt + alsa + jack = dead computer