From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755310AbdDORbU (ORCPT ); Sat, 15 Apr 2017 13:31:20 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:44485 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755154AbdDORbR (ORCPT ); Sat, 15 Apr 2017 13:31:17 -0400 Message-Id: <20170415171652.331526644@linutronix.de> User-Agent: quilt/0.63-1 Date: Sat, 15 Apr 2017 19:01:20 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior , Benjamin Herrenschmidt , Michael Ellerman , linuxppc-dev@lists.ozlabs.org Subject: [patch 13/20] powerpc/powernv: Use stop_machine_locked() References: <20170415170107.643253702@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=powerpcpowernv_Use_stop_machine_locked.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Signed-off-by: Thomas Gleixner Cc: Benjamin Herrenschmidt Cc: Michael Ellerman Cc: linuxppc-dev@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 */ mb(); - stop_machine(cpu_update_split_mode, &new_mode, cpu_online_mask); + stop_machine_locked(cpu_update_split_mode, &new_mode, cpu_online_mask); put_online_cpus();