[PATCH v4 -next 06/12] cgroup/cpuset: add callback_lock helper

[Chen Ridong]

To modify cpuset, both cpuset_mutex and callback_lock are needed. Add
helpers for cpuset-v1 to get callback_lock.

Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
---
 kernel/cgroup/cpuset-internal.h |  2 ++
 kernel/cgroup/cpuset.c          | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/kernel/cgroup/cpuset-internal.h b/kernel/cgroup/cpuset-internal.h
index 02c4b0c74fa9..9a60dd6681e4 100644
--- a/kernel/cgroup/cpuset-internal.h
+++ b/kernel/cgroup/cpuset-internal.h
@@ -239,6 +239,8 @@ static inline int is_spread_slab(const struct cpuset *cs)
 }
 
 void rebuild_sched_domains_locked(void);
+void callback_lock_irq(void);
+void callback_unlock_irq(void);
 
 /*
  * cpuset-v1.c
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 0a3347e4dddc..2b2dc963299b 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -269,6 +269,16 @@ void cpuset_unlock(void)
 
 static DEFINE_SPINLOCK(callback_lock);
 
+void callback_lock_irq(void)
+{
+	spin_lock_irq(&callback_lock);
+}
+
+void callback_unlock_irq(void)
+{
+	spin_unlock_irq(&callback_lock);
+}
+
 static struct workqueue_struct *cpuset_migrate_mm_wq;
 
 static DECLARE_WAIT_QUEUE_HEAD(cpuset_attach_wq);
-- 
2.34.1