On Sun, 2008-01-27 at 05:46 +0100, Mike Galbraith wrote: > On Sat, 2008-01-26 at 17:59 -0800, Fernando Lopez-Lezcano wrote: > > > Hi Ingo... back to testing. > > History: > > > > 2.6.23.x + rt has not been very usable for audio applications. > > 2.6.24-rt1: same so far. > > > > Why: Jack keeps printing "delayed..." messages and has xruns which means > > that somehow the timing is delayed more than what jack would think > > reasonable. As in the case with an old timing bug, the problem > > dissapears when booting the kernel with idle=poll. Other users of Planet > > CCRMA are able to replicate the behavior, which goes away with idle=poll > > or booting the machine with only one core. As a workaround I have been > > packaging 2.6.22.x but now I'm not able to use that as the old rt14 > > patch, suitably tweaked results in a non working kernel. > > > > So it looks like, again, timing is getting skewed when the jack process > > jumps between cpus and thus jack sees timing jumps that are just not > > happenning. > > > > This is with a build based on 2.6.24 using as a base the latest Fedora > > rawhide source package plus 2.6.24-rt1. > > Do you have a simple testcase? (one which doesn't entail installing > ccrma and becoming an audiophile)
No, I don't at this point. I'll see if I can cook something simple today... (naively thinking that some short C code could test for the clock being actually monotonic across cpus). -- Fernando -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
