Re: [Jack-Devel] new IIO driver added to jack - large overruns

On Tuesday 21 January 2014 13:48:55 Matt Flax wrote:
> I have found that jack isn't pulling much cpu time at all when operating
> the iio driver. Top reports that it chews about 3% of the cpu power.
> This suggests that a lot of the delay is coming from kernel related
> servicing of the iio read calls.
> 
> The small overruns can probably be removed by reading from the DMA
> buffer in the background, but I would need to do some form of locking
> and unlocking ... whether it be polling in user space or some atomic
> lock system ...
> Does anyone have suggestions on what can be used for locking or user
> space polling - something approved by jack ?
> Also it may be a good idea to have separate reading threads ... one for
> each IIO device ... any pointers ?

Consider using OProfile first (using kernel with debugging symbols and 
"opcontrol --vmlinux=..."), to get a more precise picture which part of the 
system is consuming most of the time.

CU
Christian

1390309259.9555_0.ltw:2,a <201401211301.14467.schoenebeck at crudebyte dot com>