<br><br><div><span class="gmail_quote">On 10/4/07, <b class="gmail_sendername">Florian Schmidt</b> <<a href="mailto:mista.tapas@gmx.net">mista.tapas@gmx.net</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>Well, with a vanilla kernel you simply don't get the fine grained control over<br>what code gets the cpu at what times as with a realtime-preemption kernel..<br><br>It is true that for many people a vanilla kernel with CONFIG_PREEMPT and
<br>CONFIG_HZ=1000 delivers great performance, probably even better than<br>a "lowlatency" 2.4.x kernel. But basically one badly behaving kernel driver<br>might cause delay, so for differing people the results differ. With a -rt
<br>kernel you would just give this device a nice and low prio, so it doesn't<br>even get a chance to disturb the soundcard/jack..</blockquote><div><br>I'm a big fan of my rt-patched kernel; I'm also a big fan of taking out most of the distro's default stuff from the kernel. One of these days I will compile an rt kernel with no network support even - my soundcard shares an IRQ with eth1, I don't know if this will help or not.
<br>But isn't it a nice and high prio? As in, the chrt prio? I understood this as different from the nice prio, no? I may not be doing it correctly. I set my soundcard IRQ to something like 70, jackd to something like 65, and Pd to something like 60. The Pd GUI I set a little lower yet. Do I also have to renice these apps?
<br><br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">This goes as far that if one sees an xrun while running a properly<br>setup -rt-kernel one knows it's an application bug or a soundcard driver
<br>bug ;) The kernel itself or any userland processes (X, cronjobs, whatever) as<br>a source of timing problems are pretty much eliminated.</blockquote><div><br>I get visible xruns but not audible so far. I am guessing I have the wrong buffer sizes between Pd, Csound, and jackd...
<br><br>-Chuckk<br clear="all"></div></div><br>-- <br><a href="http://www.badmuthahubbard.com">http://www.badmuthahubbard.com</a>