[PATCH] (Updated) Preemptible Kernel

[Robert Love]

This patch enables a preemptible kernel - now userspace programs can be
preempted, even if in kernel land.  This should result in greater system
response.

Updated patches are available at:
http://tech9.net/rml/linux/patch-rml-2.4.9-ac12-preempt-kernel-1 and
http://tech9.net/rml/linux/patch-rml-2.4.10-pre11-preempt-kernel-1
for 2.4.9-ac12 and 2.4.10-pre11, respectively.

ChangeLog is at http://tech9.net/rml/linux/changelog-preempt

The Athlon-optimized problem is fixed and a final solution is merged.

We have had reported success with XFS, although a patch is required to
compile, available at
http://tech9.net/rml/linux/other/patch-rml-2.4.10-pre10-xfs-preempt-fix-1

Finally, I have gotten great feedback from SMP users -- both in that "it
works" and that benchmarks show an improvement.  Thus, SMP and
preemption together are no longer marked experimental.

The only outstanding issue is a possible issue with ReiserFS, although I
am beginning to think this is attributed to VM muck and not ReiserFS. 
If you use ReiserFS, I would appreciate some feedback. (Note that the
issue is _not_ fs corruption or anything of the ilk, just odd syslog
messages and the such).

Please continue to supply feedback and relevant benchmarks.  I really
encourage "regular" users to try this out -- patch your kernel and
enable CONFIG_PREEMPT.  I am not an audio guy, trust me -- this is worth
it for any desktop.

-- 
Robert M. Love
rml at ufl.edu
rml at tech9.net