From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753280AbcFGF5Q (ORCPT ); Tue, 7 Jun 2016 01:57:16 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:32814 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125AbcFGF5P (ORCPT ); Tue, 7 Jun 2016 01:57:15 -0400 From: Lianwei Wang To: tglx@linutronix.de, peterz@infradead.org, oleg@redhat.com, mingo@kernel.org Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Lianwei Wang Subject: [PATCH v2] cpu/hotplug: handle unbalanced hotplug enable/disable Date: Mon, 6 Jun 2016 22:57:01 -0700 Message-Id: <1465279021-3299-1-git-send-email-lianwei.wang@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently it just print a warning message but did not reset cpu_hotplug_disabled when the enable/disable is unbalanced. The unbalanced enable/disable will lead the cpu hotplug work abnormally. Do nothing if an unablanced hotplug enable detected. Signed-off-by: Lianwei Wang --- kernel/cpu.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index 3e3f6e49eabb..8011b1e40523 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -245,6 +245,19 @@ void cpu_hotplug_done(void) cpuhp_lock_release(); } +static void _cpu_hotplug_disable(void) +{ + cpu_hotplug_disabled++; +} + +static void _cpu_hotplug_enable(void) +{ + if (WARN(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n")) + return; + + cpu_hotplug_disabled--; +} + /* * Wait for currently running CPU hotplug operations to complete (if any) and * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects @@ -255,7 +268,7 @@ void cpu_hotplug_done(void) void cpu_hotplug_disable(void) { cpu_maps_update_begin(); - cpu_hotplug_disabled++; + _cpu_hotplug_disable(); cpu_maps_update_done(); } EXPORT_SYMBOL_GPL(cpu_hotplug_disable); @@ -263,7 +276,7 @@ EXPORT_SYMBOL_GPL(cpu_hotplug_disable); void cpu_hotplug_enable(void) { cpu_maps_update_begin(); - WARN_ON(--cpu_hotplug_disabled < 0); + _cpu_hotplug_enable(); cpu_maps_update_done(); } EXPORT_SYMBOL_GPL(cpu_hotplug_enable); @@ -1071,7 +1084,7 @@ int disable_nonboot_cpus(void) * this even in case of failure as all disable_nonboot_cpus() users are * supposed to do enable_nonboot_cpus() on the failure path. */ - cpu_hotplug_disabled++; + _cpu_hotplug_disable(); cpu_maps_update_done(); return error; @@ -1091,7 +1104,7 @@ void enable_nonboot_cpus(void) /* Allow everyone to use the CPU hotplug again */ cpu_maps_update_begin(); - WARN_ON(--cpu_hotplug_disabled < 0); + _cpu_hotplug_enable(); if (cpumask_empty(frozen_cpus)) goto out; -- 1.9.1