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From: chengming.zhou@linux.dev
To: mingo@redhat.com, peterz@infradead.org, ycliang@andestech.com
Cc: juri.lelli@redhat.com, vincent.guittot@linaro.org,
	dietmar.eggemann@arm.com, rostedt@goodmis.org,
	bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
	vschneid@redhat.com, zhouchengming@bytedance.com,
	linux-kernel@vger.kernel.org
Subject: [PATCH] sched/fair: Fix cfs_rq_is_decayed() on !SMP
Date: Fri, 18 Aug 2023 19:35:37 +0800	[thread overview]
Message-ID: <20230818113537.2231129-1-chengming.zhou@linux.dev> (raw)
In-Reply-To: <ZN87UsqkWcFLDxea@swlinux02>

From: Chengming Zhou <zhouchengming@bytedance.com>

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

But sched debug interface use it to print per-cfs_rq stats, which
maybe better to change to use walk_tg_tree_from() instead.

This patch just fix the !SMP version 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 Liang <ycliang@andestech.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 kernel/sched/fair.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a80a73909dc2..00ef7e86a95b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4654,6 +4654,8 @@ 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)
 {
+	if (cfs_rq->load.weight)
+		return false;
 	return true;
 }
 
-- 
2.41.0


  reply	other threads:[~2023-08-18 11:38 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-18  9:35 PROBLEM: LTP cfs_bandwidth01 test bumped into SCHED_WARN_ON after de-selecting CONFIG_SMP Leo Liang
2023-08-18  9:35 ` Leo Liang
2023-08-18 11:35 ` chengming.zhou [this message]
2023-08-18 12:25   ` [PATCH] sched/fair: Fix cfs_rq_is_decayed() on !SMP Vincent Guittot
2023-08-18 13:17     ` Chengming Zhou
2023-08-18 13:21 ` [PATCH v2] " chengming.zhou
2023-08-21  1:29   ` Leo Liang
2023-08-21 11:59   ` Vincent Guittot

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