On Mon, 2009-02-02 at 09:53 +0100, Lars-Erik Helander wrote:
Users are posting success with 2.6.28.*
> (Information on what, in this context, was added in different
No AFAIK. Non-rt patched kernels do not have irq processes running as
separate SCHED_FIFO threads (which is what is tuned by rtirq).
> - Do I have to use PAM to have non-root users to acquire necessary rtprios?
I guess it depends on the distro. In most (all?) you have to make sure
the user is allowed to use SCHED_FIFO and lock memory
in /etc/security/limits.conf. That may be already done by your distro -
in some cases you have to add your user to a group for things to work
(and then logout and login again).
> - What jackd settings are important?
Depends a bit on the soundcard.
-R --> to use SCHED_FIFO
-d --> point to your hardware device (ie: hw:0 for the first card)
-p --> say, 128, for low latency
-n --> some hda-intel cards on not so new kernels may need 3 or more
> - Do I need to assign rtprios explicitly to all my processes
Automagic. Jackd gives the proper priority to the clients (to the thread
of the client that handles audio i/o)
> - Do I need to modify anything else under /sys or /proc for the
Hmmm, I did not have to but apparently newer kernels need some tweaking
(see other messages in this thread)
> I have close to 30 years experience in developing realtime systems and
Ah, I have not tried this yet! How did that work out? Any errors or
problems on boot? How exactly did you go about building the whole thing?
> However I have no experience in using newer non-RT
Planet CCRMA (http://ccrma.stanford.edu/planetccrma/software/) has rt
patched kernels of the 18.104.22.168* flavor for fc9 (in the "testing"
repository) and fc10, and should be easy to install (not an objective
assessment, I created and maintain Planet CCRMA :-).
There are many other distros out there that have rt kernels as well.
> Any knowledge or link that would enlighten me are highly appreciated.
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