Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix migration thread runtime bogosity
  sched,rt: fix isolated CPUs leaving root_task_group indefinitely throttled
  sched,cgroup: Fix up task_groups list
  sched: fix divide by zero at {thread_group,task}_times
  sched, cgroup: Reduce rq->lock hold times for large cgroup hierarchies

1 files changed, 21 insertions, 14 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 82ad284f823b..fbf1fd098dc6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3142,6 +3142,20 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 # define nsecs_to_cputime(__nsecs)	nsecs_to_jiffies(__nsecs)
 #endif
 
+static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total)
+{
+	u64 temp = (__force u64) rtime;
+
+	temp *= (__force u64) utime;
+
+	if (sizeof(cputime_t) == 4)
+		temp = div_u64(temp, (__force u32) total);
+	else
+		temp = div64_u64(temp, (__force u64) total);
+
+	return (__force cputime_t) temp;
+}
+
 void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 {
 	cputime_t rtime, utime = p->utime, total = utime + p->stime;
@@ -3151,13 +3165,9 @@ 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 = (__force u64) rtime;
-
-		temp *= (__force u64) utime;
-		do_div(temp, (__force u32) total);
-		utime = (__force cputime_t) temp;
-	} else
+	if (total)
+		utime = scale_utime(utime, rtime, total);
+	else
 		utime = rtime;
 
 	/*
@@ -3184,13 +3194,9 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
 	total = cputime.utime + cputime.stime;
 	rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
 
-	if (total) {
-		u64 temp = (__force u64) rtime;
-
-		temp *= (__force u64) cputime.utime;
-		do_div(temp, (__force u32) total);
-		utime = (__force cputime_t) temp;
-	} else
+	if (total)
+		utime = scale_utime(cputime.utime, rtime, total);
+	else
 		utime = rtime;
 
 	sig->prev_utime = max(sig->prev_utime, utime);
@@ -7246,6 +7252,7 @@ int in_sched_functions(unsigned long addr)
 
 #ifdef CONFIG_CGROUP_SCHED
 struct task_group root_task_group;
+LIST_HEAD(task_groups);
 #endif
 
 DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);