<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">I used 3.18.25 from <a href="http://kernel.org" class="">kernel.org</a>, applied this patch: <a href="https://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patch-3.18.25-rt23.patch.gz" class="">patch-3.18.25-rt23.patch.gz</a>.<div class="">The only option is changed from the default was "<span style="line-height: 14px;" class="">Fully Preemptible Kernel (RT)”. </span></div><div class=""><span style="line-height: 14px;" class="">After that I had to edit </span> kernel/locking/locktorture.c. an comment out the line</div><div class=""><div style="margin: 0px;" class=""><br class=""></div><div style="margin: 0px;" class="">#include <linux/rwlock.h></div></div><div class=""><br class=""></div><div class="">or it wouldn’t compile. (this part took me a while to figure out).</div><div class=""><br class=""></div><div class="">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…</div><div class=""><br class=""></div><div class="">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.</div><div class="">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 :-)</div><div class="">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…</div><div class=""><br class=""></div><div class="">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 :-)</div><div class=""><br class=""></div><div class="">cheers.</div><div class="">Fokke</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Feb 8, 2016, at 12:14 , Harry van Haaren <<a href="mailto:harryhaaren@gmail.com" class="">harryhaaren@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="gmail_extra"><div class="gmail_quote">On Mon, Feb 8, 2016 at 10:07 AM, Fokke de Jong <span dir="ltr" class=""><<a href="mailto:fokkedejong@gmail.com" target="_blank" class="">fokkedejong@gmail.com</a>></span> wrote:<br class=""><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">And the result is super-stable audio with a period of 32 samples @48Khz (for a total roundtrip latency of 3.5ms).<br class=""></blockquote><div class=""><br class=""></div><div class="">Congrats, that's pretty solid! Would you share some details on what config options you used, and which kernel it is?</div><div class=""><br class=""></div><div class="">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.</div></div><div class="gmail_extra"><br class=""></div>Cheers, -Harry<br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div class="gmail_signature"><br class=""><a href="http://www.openavproductions.com/" target="_blank" class="">http://www.openavproductions.com</a></div>
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