Merge tag 'sched_urgent_for_v5.18_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

42740a2f · Linus Torvalds <[email protected]> · 2022-04-24 13:28:06 -07:00

Pull scheduler fix from Borislav Petkov:

 - Fix a corner case when calculating sched runqueue variables

That fix also removes a check for a zero divisor in the code, without
mentioning it.  Vincent clarified that it's ok after I whined about it:

  https://lore.kernel.org/all/CAKfTPtD2QEyZ6ADd5WrwETMOX0XOwJGnVddt7VHgfURdqgOS-Q@mail.gmail.com/

* tag 'sched_urgent_for_v5.18_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/pelt: Fix attach_entity_load_avg() corner case

Commit: 42740a2ff5d3f2cc0c73876dfb37ed0b88d926fd
Parents: 5206548f · 40f5aa4c

Merge commit. Changes below are compared with the first parent: 5206548f.

Changes

1 files changed · +5 −5

File	Status	Add	Del	Content
kernel/sched/fair.c	modified	+5	−5	View file

kernel/sched/fair.c

View file

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d4bd299..a68482d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3829,11 +3829,11 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s
 
 	se->avg.runnable_sum = se->avg.runnable_avg * divider;
 
-	se->avg.load_sum = divider;
-	if (se_weight(se)) {
-		se->avg.load_sum =
-			div_u64(se->avg.load_avg * se->avg.load_sum, se_weight(se));
-	}
+	se->avg.load_sum = se->avg.load_avg * divider;
+	if (se_weight(se) < se->avg.load_sum)
+		se->avg.load_sum = div_u64(se->avg.load_sum, se_weight(se));
+	else
+		se->avg.load_sum = 1;
 
 	enqueue_load_avg(cfs_rq, se);
 	cfs_rq->avg.util_avg += se->avg.util_avg;