[RFC PATCH] ARM: smp: Fix the CPU hotplug race with scheduler.

[Russell King - ARM Linux]

On Mon, Jun 20, 2011 at 02:53:59PM +0530, Santosh Shilimkar wrote:
> The current ARM CPU hotplug code suffers from couple of race conditions
> in CPU online path with scheduler.
> The ARM CPU hotplug code doesn't wait for hot-plugged CPU to be marked
> active as part of cpu_notify() by the CPU which brought it up before
> enabling interrupts.

Hmm, why not just move the set_cpu_online() call before notify_cpu_starting()
and add the wait after the set_cpu_online() ?