set_subcores_per_core() holds get_online_cpus() while invoking stop_machine().
stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.
Use stop_machine_cpuslocked() to avoid the nested call.
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: linuxppc-...@lists.ozlabs.org
---
arch/powerpc/platforms/powernv/subcore.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/powerpc/platforms/powernv/subcore.c
+++ b/arch/powerpc/platforms/powernv/subcore.c
@@ -356,7 +356,8 @@ static int set_subcores_per_core(int new
/* Ensure state is consistent before we call the other cpus */
mb();
- stop_machine(cpu_update_split_mode, &new_mode, cpu_online_mask);
+ stop_machine_cpuslocked(cpu_update_split_mode, &new_mode,
+ cpu_online_mask);
put_online_cpus();
