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authorGautham R. Shenoy <ego@linux.vnet.ibm.com>2014-03-11 02:04:03 +0530
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-03-20 13:43:40 +0100
commita19423b98704aa85e84097be6d1d44a8615c2340 (patch)
tree9e0030a7414998cd016d919cf4f9cc395785cb9a /kernel/cpu.c
parentdcb99fd9b08cfe1afe426af4d8d3cbc429190f15 (diff)
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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 <mingo@kernel.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index deff2e693766..33caf5e97701 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -19,6 +19,7 @@
#include <linux/mutex.h>
#include <linux/gfp.h>
#include <linux/suspend.h>
+#include <linux/lockdep.h>
#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();
}
/*