From: Vincent Guittot <vincent.guittot@linaro.org>
Date: Thu, 27 Feb 2020 16:41:15 +0100
Subject: [PATCH] sched/fair: Fix runnable_avg for throttled cfs
References: bnc#1155798 (CPU scheduler functional and performance backports)
Patch-mainline: v5.7-rc1
Git-commit: 6212437f0f6043e825e021e4afc5cd63e248a2b4
When a cfs_rq is throttled, its group entity is dequeued and its running
tasks are removed. We must update runnable_avg with the old h_nr_running
and update group_se->runnable_weight with the new h_nr_running at each
level of the hierarchy.
Reviewed-by: Ben Segall <bsegall@google.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fixes: 9f68395333ad ("sched/pelt: Add a new runnable average signal")
Link: https://lkml.kernel.org/r/20200227154115.8332-1-vincent.guittot@linaro.org
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
kernel/sched/fair.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8fc6eb1f634c..095e33d05de3 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4704,8 +4704,13 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
if (!se->on_rq)
break;
- if (dequeue)
+ if (dequeue) {
dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP);
+ } else {
+ update_load_avg(qcfs_rq, se, 0);
+ se_update_runnable(se);
+ }
+
qcfs_rq->h_nr_running -= task_delta;
qcfs_rq->idle_h_nr_running -= idle_task_delta;
@@ -4773,8 +4778,13 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
enqueue = 0;
cfs_rq = cfs_rq_of(se);
- if (enqueue)
+ if (enqueue) {
enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
+ } else {
+ update_load_avg(cfs_rq, se, 0);
+ se_update_runnable(se);
+ }
+
cfs_rq->h_nr_running += task_delta;
cfs_rq->idle_h_nr_running += idle_task_delta;