[LAU] : jack CPU % is going crazy !

[Pieter Palmers]

Mysth-R wrote:
> 
> 
> 2008/4/7, Pieter Palmers <pieterp at joow.be <mailto:pieterp at joow.be>>:
> 
>     Mysth-R wrote:
> 
>         I forgot to precise that my sound card is a Presonus Firebox and
>         run with Freebob.
>         I got the idea to test with my U-control Uca202 (Behringer) Usb
>         sound-card, and there is no problems. The cpu percent is quite
>         stable around 2,1%.
>         It is a bit strange because I got the rtirq script congiured for
>         my firewire card. So it should not work better than my firewire ...
> 
>         I am a bit lost !!  :O[
> 
> 
>     Is the 'real' cpu time (e.g. from top) also that high? It could be
>     that there is a bug in the time reporting of the freebob backend,
>     resulting in a bad calculation of the cpu time.
> 
>     Greets,
> 
>     Pieter
> 
> 
> 
> Hi,
> It is very strange. I can't see a real correlation between cpu load 
> displayed by htop and the DSP load displayed by qjackctl.
> In htop the cpu is quite unstable too, but it doesn'tt change at the 
> same time as the dsp load in qjackctl. Perhaps it is due to a latency. 
> but I can't say if is linked.
> I have made some more test :
> 
> 1- runing qjackctl with freebob backend : both dsp load (qjackctl) and 
> cpu load (htop) are unstable but not really linked.
> 2- runing qjackctl with alsa backend : dsp load is quite stable but cpu 
> load is unstable.
> 3- running jackdmp in a console with Freebob then alsa : cpu load is 
> unstable.
> 4- when jackdmp or qjackctl are killed : cpu load is normal around 2% 
> and stable.
> 
> So :
> Is it normal that the cpu load displayed in htop is unstable ?
> If it is, then as you said pieter, could it be a bug with freebob ??? I 
> never saw this before, on the same laptop but with 32bits OS.
FreeBoB is guaranteed 110% bug-free.

> Is there a problem in my kernel config ?
> Is there a something wrong with jack or freebob with the 64bits arch ?
It could very well be a 64bit issue somewhere. I haven't tested freebob 
on 64bit yet.

> 
> 
> Well, if someone as some idea for me to make more tests ... I would be 
> happy ;)

It might be interesting if you could figure out exactly what the 
differences are between your setups. Mainly software versions etc...

Greets,

Pieter