From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932720AbdDRTuk (ORCPT ); Tue, 18 Apr 2017 15:50:40 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:53082 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932639AbdDRTue (ORCPT ); Tue, 18 Apr 2017 15:50:34 -0400 Message-Id: <20170418170553.274229815@linutronix.de> User-Agent: quilt/0.63-1 Date: Tue, 18 Apr 2017 19:04:53 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior , Will Deacon , Mark Rutland , Russell King , linux-arm-kernel@lists.infradead.org Subject: [patch V2 11/24] ARM/hw_breakpoint: Use cpuhp_setup_state_cpuslocked() References: <20170418170442.665445272@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=ARMhw_breakpoint_Use_cpuhp_setup_state_locked.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sebastian Andrzej Siewior arch_hw_breakpoint_init() holds get_online_cpus() while registerring the hotplug callbacks. cpuhp_setup_state() invokes get_online_cpus() as well. This is correct, but prevents the conversion of the hotplug locking to a percpu rwsem. Use cpuhp_setup_state_cpuslocked() to avoid the nested call. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Will Deacon Cc: Mark Rutland Cc: Russell King Cc: linux-arm-kernel@lists.infradead.org --- arch/arm/kernel/hw_breakpoint.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -1098,8 +1098,9 @@ static int __init arch_hw_breakpoint_ini * assume that a halting debugger will leave the world in a nice state * for us. */ - ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm/hw_breakpoint:online", - dbg_reset_online, NULL); + ret = cpuhp_setup_state_cpuslocked(CPUHP_AP_ONLINE_DYN, + "arm/hw_breakpoint:online", + dbg_reset_online, NULL); unregister_undef_hook(&debug_reg_hook); if (WARN_ON(ret < 0) || !cpumask_empty(&debug_err_mask)) { core_num_brps = 0;