From a19423b98704aa85e84097be6d1d44a8615c2340 Mon Sep 17 00:00:00 2001 From: "Gautham R. Shenoy" Date: Tue, 11 Mar 2014 02:04:03 +0530 Subject: CPU hotplug: Add lockdep annotations to get/put_online_cpus() Add lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin()/cpu_hotplug_end(). Cc: Ingo Molnar Reviewed-by: Oleg Nesterov Signed-off-by: Gautham R. Shenoy Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki diff --git a/kernel/cpu.c b/kernel/cpu.c index deff2e6..33caf5e 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "smpboot.h" @@ -57,17 +58,30 @@ static struct { * an ongoing cpu hotplug operation. */ int refcount; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif } cpu_hotplug = { .active_writer = NULL, .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), .refcount = 0, +#ifdef CONFIG_DEBUG_LOCK_ALLOC + .dep_map = {.name = "cpu_hotplug.lock" }, +#endif }; +/* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ +#define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map) +#define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) +#define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) + void get_online_cpus(void) { might_sleep(); if (cpu_hotplug.active_writer == current) return; + cpuhp_lock_acquire_read(); mutex_lock(&cpu_hotplug.lock); cpu_hotplug.refcount++; mutex_unlock(&cpu_hotplug.lock); @@ -87,6 +101,7 @@ void put_online_cpus(void) if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) wake_up_process(cpu_hotplug.active_writer); mutex_unlock(&cpu_hotplug.lock); + cpuhp_lock_release(); } EXPORT_SYMBOL_GPL(put_online_cpus); @@ -117,6 +132,7 @@ void cpu_hotplug_begin(void) { cpu_hotplug.active_writer = current; + cpuhp_lock_acquire(); for (;;) { mutex_lock(&cpu_hotplug.lock); if (likely(!cpu_hotplug.refcount)) @@ -131,6 +147,7 @@ void cpu_hotplug_done(void) { cpu_hotplug.active_writer = NULL; mutex_unlock(&cpu_hotplug.lock); + cpuhp_lock_release(); } /* -- cgit v0.10.2