[PATCH 6/8] lockdep: annotate cpu_hotplug

Gautham R Shenoy
2008-04-29T13:03:22Z

Subject: lockdep: annotate cpu_hotplug

From: Peter Zijlstra <a.p.zijlstra@chello.nl>

Annotate the cpu_hotplug lock.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
---

include/linux/lockdep.h | 15 +++++++++++++++
kernel/cpu.c | 16 ++++++++++++++++
2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 36e254f..424db2f 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -458,4 +458,19 @@ static inline void print_irqtrace_events(struct task_struct *curr)
# define rwsem_release(l, n, i) do { } while (0)
#endif

+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# ifdef CONFIG_PROVE_LOCKING
+# define cpu_hotplug_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, i)
+# define cpu_hotplug_acquire_read(l, s, t, i) lock_acquire(l, s, t, 3, 2, i)
+# else
+# define cpu_hotplug_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, i)
+# define cpu_hotplug_acquire_read(l, s, t, i) lock_acquire(l, s, t, 3, 1, i)
+# endif
+# define cpu_hotplug_release(l, n, i) lock_release(l, n, i)
+#else
+# define cpu_hotplug_acquire(l, s, t, i) do { } while (0)
+# define cpu_hotplug_acquire_read(l, s, t, i) do { } while (0)
+# define cpu_hotplug_release(l, n, i) do { } while (0)
+#endif
+
#endif /* __LINUX_LOCKDEP_H */
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e856c22..8f1718f 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -35,12 +35,20 @@ static struct {
int refcount;
wait_queue_head_t reader_queue;
wait_queue_head_t writer_queue;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
} cpu_hotplug;

#define writer_exists() (cpu_hotplug.active_writer != NULL)

void __init cpu_hotplug_init(void)
{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ static struct lock_class_key __key;
+
+ lockdep_init_map(&cpu_hotplug.dep_map, "cpu_hotplug", &__key, 0);
+#endif
cpu_hotplug.active_writer = NULL;
spin_lock_init(&cpu_hotplug.lock);
cpu_hotplug.refcount = 0;
@@ -54,6 +62,8 @@ void get_online_cpus(void)
{
might_sleep();

+ cpu_hotplug_acquire_read(&cpu_hotplug.dep_map, 0, 0, _THIS_IP_);
+
spin_lock(&cpu_hotplug.lock);
if (cpu_hotplug.active_writer == current)
goto unlock;
@@ -80,6 +90,8 @@ EXPORT_SYMBOL_GPL(get_online_cpus);

void put_online_cpus(void)
{
+ cpu_hotplug_release(&cpu_hotplug.dep_map, 1, _THIS_IP_);
+
spin_lock(&cpu_hotplug.lock);
if (cpu_hotplug.active_writer == current)
goto unlock;
@@ -119,6 +131,8 @@ static void cpu_hotplug_begin(void)
{
might_sleep();

+ cpu_hotplug_acquire(&cpu_hotplug.dep_map, 0, 0, _THIS_IP_);
+
spin_lock(&cpu_hotplug.lock);
if (cpu_hotplug.refcount || cpu_hotplug.active_writer) {
DEFINE_WAIT(wait);
@@ -140,6 +154,8 @@ static void cpu_hotplug_begin(void)

static void cpu_hotplug_done(void)
{
+ cpu_hotplug_release(&cpu_hotplug.dep_map, 1, _THIS_IP_);
+
spin_lock(&cpu_hotplug.lock);
cpu_hotplug.active_writer = NULL;
if (!list_empty(&cpu_hotplug.writer_queue.task_list))
--
Thanks and Regards
gautham