powerpc/powernv: Protect split-core operations from CPU hotplug
During split-core operations, one of the online CPUs is nominated as the
"master" and then stop_machine() is invoked to perform the split/unsplit
procedure. Between these 2 steps, if CPU hotplug occurs and takes the
just nominated "master" CPU offline, then the split/unsplit procedure
does not complete properly and leads to undesirable effects.
So protect the entire split-core operation with get/put_online_cpus()
to synchronize with CPU hotplug.
Fixes bz 105509.
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
1 file changed
