Commit 6e32d479 authored Nov 13, 2012 by Fenghua Yu Committed by H. Peter Anvin Nov 14, 2012

kernel/cpu.c: Add comment for priority in cpu_hotplug_pm_callback



cpu_hotplug_pm_callback should have higher priority than
bsp_pm_callback which depends on cpu_hotplug_pm_callback to disable cpu hotplug
to avoid race during bsp online checking.

This is to hightlight the priorities between the two callbacks in case people
may overlook the order.

Ideally the priorities should be defined in macro/enum instead of fixed values.
To do that, a seperate patchset may be pushed which will touch serveral other
generic files and is out of scope of this patchset.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-7-git-send-email-fenghua.yu@intel.com


Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

parent 209efae1

kernel/cpu.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -601,6 +601,11 @@ cpu_hotplug_pm_callback(struct notifier_block *nb,

		static int __init cpu_hotplug_pm_sync_init(void)
		{
		/*
		* cpu_hotplug_pm_callback has higher priority than x86
		* bsp_pm_callback which depends on cpu_hotplug_pm_callback
		* to disable cpu hotplug to avoid cpu hotplug race.
		*/
		pm_notifier(cpu_hotplug_pm_callback, 0);
		return 0;
		}