Re: [linux-audio-user] Realtime kernel.

Wednesday 29 November 2006 11:17, J M Needham:
> I found
> http://repos.opensuse.org/home:/appleonkel/SUSE_Linux_10.1/i586/kernel-rt-d
>efault-2.6.18-8.5.i586.rpm on the internet while looking for info on how to
> patch a realtime kernel in suse 10.1. I'm having some problems with it (it
> didn't boot; I used rpm -i ... to install it) and so if anyone has any
> experience with this or advice for SUSE 10.1 (I'm leaving suse soon anyway
> -- heading to DeMuDi) then I'd appreciate. I understand that patching a
> kernel for suse 10.1 with a realtime patch is non-trivial.
>
> Any help appreciated.
> Jonty

"Working with the suse 2.6.x kernel sources" at
http://www.suse.de/~agruen/kernel-doc/ is a generic recipe for building suse
kernels. One of the more relevant chapters would be "Patch selection
mechanism" that tells you how to fly in different patchsets.

There's a catch: Applying ingo-rt to a fully suse-patched kernel will break
things. The tricky part would be to identify interfering suse-patches that
are dispensable. This is what JAD does. It's a mess.

If what you want is keep *all* of suse's structure plus reliable low-latency
audio performance you'd follow the same recipe and change some of kernel's
configuration like stronger preemption (CONFIG_PREEMPT=y) instead of
voluntary, CONFIG_HZ_1000=y instead of 250 etc. plus blame suse out loud for
not doing so in the first place.

No ingo-rt here and and still -p 16 (~0.7 ms one way latency) is quite
useable.

-- 
Wolfgang