[PATCH] Convert kernel/cpu.c to mutexes (81615b62) · Commits · 戴 / test

Convert kernel/cpu.c from semaphore to mutex. I've reviewed all lock_cpu_hotplug() critical sections, and they all seem to fit mutex semantics. Signed-off-by:

Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

kernel/cpu.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -13,10 +13,10 @@
		#include <linux/module.h>
		#include <linux/kthread.h>
		#include <linux/stop_machine.h>
		#include <asm/semaphore.h>
		#include <linux/mutex.h>

		/* This protects CPUs going up and down... */
		static DECLARE_MUTEX(cpucontrol);
		static DEFINE_MUTEX(cpucontrol);

		static BLOCKING_NOTIFIER_HEAD(cpu_chain);

		@@ -30,9 +30,9 @@ static int __lock_cpu_hotplug(int interruptible)

		if (lock_cpu_hotplug_owner != current) {
		if (interruptible)
		ret = down_interruptible(&cpucontrol);
		ret = mutex_lock_interruptible(&cpucontrol);
		else
		down(&cpucontrol);
		mutex_lock(&cpucontrol);
		}

		/*
		@@ -56,7 +56,7 @@ void unlock_cpu_hotplug(void)
		{
		if (--lock_cpu_hotplug_depth == 0) {
		lock_cpu_hotplug_owner = NULL;
		up(&cpucontrol);
		mutex_unlock(&cpucontrol);
		}
		}
		EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);

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