[RFC patch 0/5] Per cpu thread hotplug infrastructure

Thomas Gleixner
2012-06-13T11:01:02Z

The following series implements the infrastructure for parking and
unparking kernel threads to avoid the full teardown and fork on cpu
hotplug operations along with management infrastructure for hotplug
and users.

I've converted the most obvious (and simple) users ksoftirqd and
watchdog along with a driver (the latter is untested due to lack of
hardware).

Looking at the other (ab)users of per cpu kernel threads:

- drivers/* should be rather trivial to convert all users

- RCU needs more thought, but I'm sure that Paul will figure it out
in no time :)

The main issue with RCU are the per node threads, but it should be
simple to extend the infrastructure to allow registration and
handling of per node threads as well.

- workqueues. I did not even try to think about converting it. The
hotplug related code in there causes strong feelings related to
zombies and chainsaws. (See https://lwn.net/Articles/378036/)

Thanks,

tglx