[patch 13/20] powerpc/powernv: Use stop_machine_locked()

Thomas Gleixner tglx at linutronix.de
Sun Apr 16 03:01:20 AEST 2017

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_locked() to avoid the nested call.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: linuxppc-dev at lists.ozlabs.org

 arch/powerpc/platforms/powernv/subcore.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/platforms/powernv/subcore.c
+++ b/arch/powerpc/platforms/powernv/subcore.c
@@ -356,7 +356,7 @@ static int set_subcores_per_core(int new
 	/* Ensure state is consistent before we call the other cpus */
-	stop_machine(cpu_update_split_mode, &new_mode, cpu_online_mask);
+	stop_machine_locked(cpu_update_split_mode, &new_mode, cpu_online_mask);

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