In the 2.6.21 kernel there are still 3 hotplug issues that are cpuset-
related, and that I find to still be problems. And for which I offer
patches.
These have been submitted before, and subsequently cleaned up per
comments received. I'm resubmitting all 3 for consideration and further
comment.
1) [PATCH 1/1] hotplug cpu: cpusets/sched_domain reconciliation
2) [PATCH 1/1] hotplug cpu: move tasks in empty cpusets to parent
3) [PATCH 1/1] hotplug cpu: migrate a task within its cpuset
1) Reconciles cpusets and sched_domains that get out of sync
due to hotplug disabling and re-enabling of cpu's.
Tasks can get into infinite hangs without this fix.
kernel/cpuset.c
kernel/sched.c
2) When a cpuset is emptied by disabling its cpus, move tasks to
a parent cpuset.
This is a correction of the current procedure, which moves such
tasks to the wrong cpuset.
kernel/cpuset.c
3) Causes a task running on a disabled cpu to migrate to a cpu within
its cpuset.
This behavior is particularly important for a NUMA system on which
tasks have been explicitly placed.
kernel/sched.c