Re: [Jack-Devel] jack dsp load calculation

On 26/12/2015 12:56, Robin Gareus wrote:
> It's Mixbus that motivated me to looking into this, actually.  There are
> forum reports: "DSP load is 40% and there are x-runs".
>

That's true - but are they happening with the Jack backend?

When you and Tim first implemented your PortAudio backend (the blocking 
version) I regularly heard xruns at only 40% DSP.  But I don't see how 
you can blame them on Jack.  When running with a Jack backend I've (very 
occasionally) encountered xruns at around 92% DSP (which is why my first 
suggestion was to lower the threshold). However, I think my later 
suggestion is better (to factor in any xruns which occurred between the 
previous reading and the new one).

I'm sorry to be rude Robin but I don't think your suggestion has got 
anything to do with improving Jack.  I suspect you're trying to degrade 
Jack's figures to make them match the ones from your PortAudio backend 
(which are generally poorer).  Mixbus has been on sale for years.  Sales 
run into thousands - but I can't remember a single complaint about xruns 
happening at such low DSP loads (prior to your PortAudio backend coming 
along).

If the new backend suffers from xrun problems, fix them.  But don't fix 
them by trying to nobble the other backends.  If Jack was suffering from 
the problem you described above, we'd have all heard about it a long 
time before now.  MB has at least 5 years of sales behind it.  So how 
come we only started noticing this problem in the past few months?

John

1451138881.28988_0.ltw:2,a <567E9F39.1090901 at tiscali dot co dot uk>