cpuset: add lockdep_assert_cpuset_lock_held helper

Add lockdep_assert_cpuset_lock_held() to allow other subsystems to verify
that cpuset_mutex is held.

Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index a98d3330385c2954fa02b472893a6c3fd68bbab3..a634489c9f123e5f6544918013d4930f5ff37216 100644 (file)
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -74,6 +74,7 @@ extern void inc_dl_tasks_cs(struct task_struct *task);
 extern void dec_dl_tasks_cs(struct task_struct *task);
 extern void cpuset_lock(void);
 extern void cpuset_unlock(void);
+extern void lockdep_assert_cpuset_lock_held(void);
 extern void cpuset_cpus_allowed_locked(struct task_struct *p, struct cpumask *mask);
 extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
 extern bool cpuset_cpus_allowed_fallback(struct task_struct *p);
@@ -195,6 +196,7 @@ static inline void inc_dl_tasks_cs(struct task_struct *task) { }
 static inline void dec_dl_tasks_cs(struct task_struct *task) { }
 static inline void cpuset_lock(void) { }
 static inline void cpuset_unlock(void) { }
+static inline void lockdep_assert_cpuset_lock_held(void) { }
 
 static inline void cpuset_cpus_allowed_locked(struct task_struct *p,
                                        struct cpumask *mask)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index fea577b4016ad4ff5c51849ae71f24f67e78f81b..4fa3080da3bee9c2d2ef104bc575c85a89d8c8ef 100644 (file)
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -271,6 +271,11 @@ void cpuset_unlock(void)
        mutex_unlock(&cpuset_mutex);
 }
 
+void lockdep_assert_cpuset_lock_held(void)
+{
+       lockdep_assert_held(&cpuset_mutex);
+}
+
 /**
  * cpuset_full_lock - Acquire full protection for cpuset modification
  *