linux-kernel - [PATCH] sched: remove unnecessary check in sched_{debug

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Message-ID: <20250807034016.43446-1-wangfushuai@baidu.com>
Date: Thu, 7 Aug 2025 11:40:16 +0800
From: Fushuai Wang <wangfushuai@...du.com>
To: <linux-kernel@...r.kernel.org>
CC: <vschneid@...hat.com>, <mgorman@...e.de>, <bsegall@...gle.com>,
	<rostedt@...dmis.org>, <dietmar.eggemann@....com>,
	<vincent.guittot@...aro.org>, <juri.lelli@...hat.com>,
	<peterz@...radead.org>, <mingo@...hat.com>, Fushuai Wang
	<wangfushuai@...du.com>
Subject: [PATCH] sched: remove unnecessary check in sched_{debug_}start()

-1 is a legal argument for cpumask_next(), and cpumask_next(-1, mask) is
equivalent to cpumask_first(mask). The explicit check and separate branch
are unnecessary.

Signed-off-by: Fushuai Wang <wangfushuai@...du.com>
---
 kernel/sched/debug.c | 5 +----
 kernel/sched/stats.c | 5 +----
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 3f06ab84d53f..1b3592bac62b 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -1080,10 +1080,7 @@ static void *sched_debug_start(struct seq_file *file, loff_t *offset)
 
 	n--;
 
-	if (n > 0)
-		n = cpumask_next(n - 1, cpu_online_mask);
-	else
-		n = cpumask_first(cpu_online_mask);
+	n = cpumask_next(n - 1, cpu_online_mask);
 
 	*offset = n + 1;
 
diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index d1c9429a4ac5..f93b1c87c538 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -181,10 +181,7 @@ static void *schedstat_start(struct seq_file *file, loff_t *offset)
 
 	n--;
 
-	if (n > 0)
-		n = cpumask_next(n - 1, cpu_online_mask);
-	else
-		n = cpumask_first(cpu_online_mask);
+	n = cpumask_next(n - 1, cpu_online_mask);
 
 	*offset = n + 1;
 
-- 
2.36.1