1 files changed, 19 insertions, 5 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 41541d79e3c8..dc85ceb90832 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1294,6 +1294,10 @@ static void resched_task(struct task_struct *p)
 static void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
 {
 }
+
+static void sched_avg_update(struct rq *rq)
+{
+}
 #endif /* CONFIG_SMP */
 
 #if BITS_PER_LONG == 32
@@ -3182,6 +3186,8 @@ static void update_cpu_load(struct rq *this_rq)
 
                 this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i;
         }
+
+        sched_avg_update(this_rq);
 }
 
 static void update_cpu_load_active(struct rq *this_rq)
@@ -3507,9 +3513,9 @@ void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
         rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
 
         if (total) {
-                u64 temp;
+                u64 temp = rtime;
 
-                temp = (u64)(rtime * utime);
+                temp *= utime;
                 do_div(temp, total);
                 utime = (cputime_t)temp;
         } else
@@ -3540,9 +3546,9 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
         rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
 
         if (total) {
-                u64 temp;
+                u64 temp = rtime;
 
-                temp = (u64)(rtime * cputime.utime);
+                temp *= cputime.utime;
                 do_div(temp, total);
                 utime = (cputime_t)temp;
         } else
@@ -3865,8 +3871,16 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
                 /*
                  * Owner changed, break to re-assess state.
                  */
-                if (lock->owner != owner)
+                if (lock->owner != owner) {
+                        /*
+                         * If the lock has switched to a different owner,
+                         * we likely have heavy contention. Return 0 to quit
+                         * optimistic spinning and not contend further:
+                         */
+                        if (lock->owner)
+                                return 0;
                         break;
+                }
 
                 /*
                  * Is that owner really running on that cpu?