[PATCH] Handle per-subsystem mutexes for CONFIG_HOTPLUG_CPU not set
Provide a common interface for all the subsystems to lock and unlock their
per-subsystem hotcpu mutexes.
When CONFIG_HOTPLUG_CPU is not set, these operations would be no-ops.
[akpm@osdl.org: macros -> inlines]
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 71dc6ba..bf00ce6 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -24,6 +24,7 @@
#include <linux/compiler.h>
#include <linux/cpumask.h>
#include <asm/semaphore.h>
+#include <linux/mutex.h>
struct cpu {
int node_id; /* The node which contains the CPU */
@@ -74,6 +75,17 @@
#ifdef CONFIG_HOTPLUG_CPU
/* Stop CPUs going up and down. */
+
+static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
+{
+ mutex_lock(cpu_hp_mutex);
+}
+
+static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
+{
+ mutex_unlock(cpu_hp_mutex);
+}
+
extern void lock_cpu_hotplug(void);
extern void unlock_cpu_hotplug(void);
#define hotcpu_notifier(fn, pri) { \
@@ -85,7 +97,14 @@
#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
int cpu_down(unsigned int cpu);
#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
-#else
+
+#else /* CONFIG_HOTPLUG_CPU */
+
+static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
+{ }
+static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
+{ }
+
#define lock_cpu_hotplug() do { } while (0)
#define unlock_cpu_hotplug() do { } while (0)
#define lock_cpu_hotplug_interruptible() 0
@@ -95,7 +114,7 @@
/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
static inline int cpu_is_offline(int cpu) { return 0; }
-#endif
+#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_SUSPEND_SMP
extern int disable_nonboot_cpus(void);