[linux-audio-dev] Re: [Jackit-devel] 2.4.20-rc1ÂÂ + lowlat +preempt + alsa + jack = dead computer

[David Olofson]

On Saturday 07 December 2002 03.58, Fernando Pablo Lopez-Lezcano 
wrote:
> > 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 :-)

I would be interested in trying your version of the patches. Please 
mail! :-)


BTW, I applied the 2.4.19 LL patch to 2.4.20, and got a few rejects 
in the file system area, which I have not investigated further. 
(Seems to be a lot of changes around there...) Performance is "ok" 
under X and proc stress, but I get countless latencies in the whole 
range up to some 6-8 ms as soon as I start stressing the disk. (This 
is *with* DMA enabled, of course.)

Haven't tried preempt yet.


As to freezing, I've only managed to do that once - and IIRC, that 
was when trying to instantiate a synth in MusE while Ardour was 
running in the background. No useful info about what actually 
happened, and I haven't tested that combination any further.

Are you certain your freeze is actually happening in kernel space? 
Tried using watchdog with "ping-pong" between highest and lowest 
priority SCHED_FIFO threads? (BTW, we should have a watchdog anyway, 
probably integrated with givertcap or something.)


//David Olofson - Programmer, Composer, Open Source Advocate

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