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-rw-r--r--kernel/sched.c24
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?