1 files changed, 15 insertions, 1 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 81e2a388a0f6..356450f09c1f 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -79,6 +79,8 @@ static struct {
 
 /* 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_tryread() \
+                                  lock_map_acquire_tryread(&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)
 
@@ -91,10 +93,22 @@ void get_online_cpus(void)
         mutex_lock(&cpu_hotplug.lock);
         cpu_hotplug.refcount++;
         mutex_unlock(&cpu_hotplug.lock);
-
 }
 EXPORT_SYMBOL_GPL(get_online_cpus);
 
+bool try_get_online_cpus(void)
+{
+        if (cpu_hotplug.active_writer == current)
+                return true;
+        if (!mutex_trylock(&cpu_hotplug.lock))
+                return false;
+        cpuhp_lock_acquire_tryread();
+        cpu_hotplug.refcount++;
+        mutex_unlock(&cpu_hotplug.lock);
+        return true;
+}
+EXPORT_SYMBOL_GPL(try_get_online_cpus);
+
 void put_online_cpus(void)
 {
         if (cpu_hotplug.active_writer == current)