(rant) Is there any hope

Rick Green rtg at aapsc.com
Wed Feb 15 17:03:46 UTC 2012


On Wed, 15 Feb 2012, Ralf Mardorf wrote:

> On Wed, 2012-02-15 at 00:11 -0500, Rick Green wrote:
>> [snip] But 10.04 wasn't stable enough to run jack
>> for more than a few minutes before the xrun count went thru the roof.
>
> I always build a kernel-rt myself. At least you should use a full
> preempted with threadirqs set to the boot parameters. There are just a
> few developers, such as the 64 Studio people, that build kernel-rt I
> like. For example Arch Linux kernels fail for my Wi-Fi, they exclude
> HPET to the rt. Ubuntu Studio 11.10 by default comes with the
> kernel-generic.
    Yeah, that was the first, worst regression down this slippery slope. 
What happened?  I would think that packaging an -rt kernel would be job 1 
for a 'studio' distro.  Especially since the RT patches were accepted into 
mainline.  I was comfortable compiling and installing kernels way back in 
the days of LILO and Linux 1.x, but I could probably count on one hand the 
number of times I've attempted it since 2.0, and I'm nowhere up to speed 
on the complexities of grub2 and initrd's, so I'm now dependent on 
distributor's packages.
   My portable recording rig runs on an early AMD_64 laptop.  The TI 
firewire and Broadcom Wifi share an IRQ, so I've long ago learned to turn 
off the Wifi before I start jack.

>
> If you get xruns, first get a kernel-rt, second check if rtirq set your
> card to the highest priority.
>
> I for example need to add "hdspm":
> RTIRQ_NAME_LIST="rtc hdspm snd usb i8042"
>
> The second might not have significant impact, but the first, a kernel-rt
> will improve a lot.
>
>> [snip] jack inexplicably dies [snip]
>
> Did you switch between Jack1 and Jack2?

Right now, I've got the default package, ISTR jackdmp v1.9.2 or 
thereabouts. (the machine's not booted at the moment).  This confuses me, 
I thought jackdmp = jack2, and jackd would show v 1.x.x.  My machine is 
just single-core, so I don't need jackdmp.  Is there a package for Jack1, 
and might it be appropriate to switch to it?

-- 
Rick Green

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."
                                   -Benjamin Franklin

"As for our common defense, we reject as false the choice between our
safety and our ideals."
                                -President Barack Obama 20 Jan 2009



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