node affine NUMA scheduler

There's a new version of the node affine NUMA scheduler extension based on the O(1) scheduler at

    http://home.arcor.de/efocht/sched/Nod18_2.4.18-ia64-O1ef7.patch

The patch is for 2.4.18 kernels and it has been tested on IA64 systems. It requires the O(1) scheduler patch with the corrected complex macros which I posted to the LSE and linux-ia64 mailing lists last week. For IA64 you should use:

    http://home.arcor.de/efocht/sched/O1_ia64-ef7-2.4.18.patch.bz2
which should be applied to   2.4.18  +  ia64-020622 patch.
For IA32 (NUMA-Q) try instead:
    http://home.arcor.de/efocht/sched/O1_i386-ef7-2.4.18.patch.bz2

What is it good for?

- Extends the scheduler to NUMA.
- Each task gets a homenode assigned at start (initial load balancing).
- A memory affinity patch (like discontigmem, or similar) should take care that the memory of the task is allocated mainly from its homenode.
- The scheduler attracts the tasks to their homenodes while trying to keep the nodes equally balanced.
- Target: keep processes and their memory on the same node to reduce memory access latencies without having to fiddle with the cpus_allowed masks (hard affinities).
- Within one node, behaves like the normal O(1) scheduler.

For an overview over the features have a look at:
http://home.arcor.de/efocht/sched

There are several changes compared to the previous version, the most important ones are:
- Extension to multilevel NUMA hierarchy by implementing delays when stealing tasks from remote nodes.
- Better selection of task to be stolen from busiest runqueue. Take into account cache coolness, node and supernode of task and runqueue.

Comments and feedback are very wellcome.

Regards,
Erich