linux v2.6.25.6.cpuisol1

linux v2.6.25.6.cpuisol1

[Max Krasnyansky]

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.

--
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.

---
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