From: Chengming Zhou <zhouchengming@bytedance.com>
Date: Wed, 13 Sep 2023 13:20:31 +0000 (+0000)
Subject: sched/fair: Fix cfs_rq_is_decayed() on !SMP
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c0490bc9bb62d9376f3dd4ec28e03ca0fef97152;p=linux.git

sched/fair: Fix cfs_rq_is_decayed() on !SMP

We don't need to maintain per-queue leaf_cfs_rq_list on !SMP, since
it's used for cfs_rq load tracking & balancing on SMP.

But sched debug interface uses it to print per-cfs_rq stats.

This patch fixes the !SMP version of cfs_rq_is_decayed(), so the
per-queue leaf_cfs_rq_list is also maintained correctly on !SMP,
to fix the warning in assert_list_leaf_cfs_rq().

Fixes: 0a00a354644e ("sched/fair: Delete useless condition in tg_unthrottle_up()")
Reported-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Closes: https://lore.kernel.org/all/ZN87UsqkWcFLDxea@swlinux02/
Link: https://lore.kernel.org/r/20230913132031.2242151-1-chengming.zhou@linux.dev
---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 41cfd61b4d6b3..c893721ff5b15 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4866,7 +4866,7 @@ static inline void update_misfit_status(struct task_struct *p, struct rq *rq)
 
 static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
 {
-	return true;
+	return !cfs_rq->nr_running;
 }
 
 #define UPDATE_TG	0x0