2.6.19-rc6-rt5

Ingo Molnar
2006-11-20T22:04:31Z

i've released the 2.6.19-rc6-rt5 tree, which can be downloaded from the
usual place:

http://redhat.com/~mingo/realtime-preempt/

the -rt YUM repository for Fedora Core 6 can be activated via:

cd /etc/yum.repos.d
wget http://people.redhat.com/~mingo/realtime-preempt/rt.repo
yum install kernel-rt

on x86_64, do:

yum install kernel-rt.x86_64

lots of fixes and improvements were done to -rt5. In particular
SMP/dual-core systems should get quite a bit faster. Changes:

- implemented proper per-cpu page allocation (PCP-list) in
page_alloc.c, for PREEMPT_RT too. (previously this code was #ifdef-ed
out and we allocated straight from the zones - but this caused the
zone lock to act as a global lock)

- speedup of PREEMPT_RT's implementation of atomic_dec_and_lock().
(this was a major bottleneck for workloads like kernel compiles.)

- more tracer features: symbolic stack backtraces embedded in
/proc/latency_trace for certain types of events, switchable syscall
tracing.

- irq-threading cleanups, based on the comments from Sergei Shtylyov,
Daniel Walker and Benjamin Herrenschmidt.

- vsyscall & tracing fixes: 'notsc' should not be required on the YUM
rpms anymore.

to build a 2.6.19-rc6-rt5 tree, the following patches should be applied:

http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.18.tar.bz2
http://kernel.org/pub/linux/kernel/v2.6/testing/patch-2.6.19-rc6.bz2
http://redhat.com/~mingo/realtime-preempt/patch-2.6.19-rc6-rt5

as usual, bugreports, fixes and suggestions are welcome,

Ingo