linux v2.6.25.6.cpuisol1

This is the latest version of my CPU isolation tree. Git tree is available at:
git://git.kernel.org/pub/scm/linux/kernel/git/maxk/cpuisol-2.6.25.y.git
http://www.kernel.org/pub/scm/linux/kernel/git/maxk/cpuisol-2.6.25.y.git

Full patch is at:
http://kernel.org/pub/linux/kernel/people/maxk/cpuisol/patches/v2.6.25.6.cpuisol1.patch

In order to simplify overall system setup I wrote a simple tool for system partitioning - "syspart". You can get the latest version from here
http://kernel.org/pub/linux/kernel/people/maxk/cpuisol/syspart/
git://git.kernel.org/pub/scm/linux/kernel/git/maxk/syspart.git

This tool takes care of setting up IRQ affinities and cpusets, moving kernel and user space tasks, bring CPUs off/online, etc. Please note that you want to disable daemons like "irqbalance" to avoid resource partitioning conflicts. For more info see syspart/README.

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I also have some sample kernel configs that have been tested and are know to work. You can pick one of them as base for your kernel:
http://kernel.org/pub/linux/kernel/people/maxk/cpuisol/configs/

Required kernel features:
CONFIG_CGROUP
CONFIG_CPUSETS
CONFIG_CPU_HOTPLUG

Following features are required if you intend on chewing ~100% in the user space SCHED_FIFO threads running on the isolated CPUs (note that OPROFILE is known to not work for this use case):
CONFIG_SLUB or CONFIG_SLOB

You may also want to disable the following features in order to achieve the lowest possible latency:
!CONFIG_HIGH_RES_TIMERS
!CONFIG_NO_HZ
!CONFIG_CPU_FREQ
And of course you want to refer to
http://rt.wiki.kernel.org/index.php/HOWTO:_Build_an_RT-application
for general guidelines on how to build RT applications.

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This version is based on a completely different approach (compared to previous cpuisol tree releases). Instead of the centralized cpu_isolation_map it's now based on the existing kernel features like cpusets. The number of changes is therefor very small.

Shortlog:
Max Krasnyansky (6):
sched: Fix memory leak in the cpu hotplug handing logic
sched: CPU hotplug events must not destroy scheduler domains created by
the cpusets
genirq: Expose default irq affinity mask (take 3)
sysctl: Add generic cpumask parser for sysctls
stopmachine: Introduce stopmachine_cpus sysctl
Linux 2.6.25.6.cpuisol1

sched: changes are simple bug fixes and are on their way into the mainline.
genirq: stuff has been ACKed in general is pending final ACK from genirq maintainer.
stopmachine change is a temporary hack to allow for module insertion and removal.

Diffstat:

 Documentation/IRQ-affinity.txt     |   37 ++++++++++++++----
 Documentation/filesystems/proc.txt |   29 +++++++++-----
 Makefile                           |    2 -
 arch/alpha/kernel/irq.c            |    5 +-
 include/linux/irq.h                |   14 ++-----
 include/linux/sysctl.h             |    2 +
 kernel/cpuset.c                    |    6 +++
 kernel/irq/manage.c                |   28 +++++++++++++-
 kernel/irq/proc.c                  |   59 +++++++++++++++++++++++++++--
 kernel/sched.c                     |   23 +++++++++++
 kernel/stop_machine.c              |    5 ++
 kernel/sysctl.c                    |   73 +++++++++++++++++++++++++++++++++++
 12 files changed, 244 insertions(+), 39 deletions(-)

Comments, questions, suggestions and bug reports are welcome. Max