[LAD] cpu spikes

[Fokke de Jong]

I used 3.18.25 from kernel.org, applied this patch: patch-3.18.25-rt23.patch.gz <https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patch-3.18.25-rt23.patch.gz>.
The only option is changed from the default was "Fully Preemptible Kernel (RT)”. 
After that I had to edit  kernel/locking/locktorture.c. an comment out the line

#include <linux/rwlock.h>

or it wouldn’t compile. (this part took me a while to figure out).

This reason I choose this kernel was to stay close the the kernel version already installed on my system (3.19.x). I have to admit, i know very little about different kernel versions…

If I would do it again, i would probably start out with the low-latency config rather than the default, but i’m not sure it it would make a difference.
One caveat though, I haven’t tested this kernel very thoroughly, so i’m not even sure it won’t blow up in my face if I were to try and send an email or something :-)
And also, I don’t seem to get hardware video acceleration (I have a intel builtin gpu). I don’t case for this too much as i plan to run this project in console only…

I’m not sure how much there is to be gained by  turning off all kinds of features in the kernel, but i know that trying this out takes a lot of time, especially if you don’t really know what you’re doing :-)

cheers.
Fokke





> On Feb 8, 2016, at 12:14 , Harry van Haaren <harryhaaren at gmail.com> wrote:
> 
> On Mon, Feb 8, 2016 at 10:07 AM, Fokke de Jong <fokkedejong at gmail.com <mailto:fokkedejong at gmail.com>> wrote:
> And the result is super-stable audio with a period of 32 samples @48Khz (for a total roundtrip latency of 3.5ms).
> 
> Congrats, that's pretty solid! Would you share some details on what config options you used, and which kernel it is?
> 
> I think it would be great if the Linux Audio community built up a list of kernel config options that need changing for optimal audio performance.
> 
> Cheers, -Harry
> 
> -- 
> 
> http://www.openavproductions.com <http://www.openavproductions.com/>
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