linux-kernel - [PATCH] clocksource: Utilize cpumask_next

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Message-ID: <20250611104506.2270561-1-richard120310@gmail.com>
Date: Wed, 11 Jun 2025 18:45:06 +0800
From: I Hsin Cheng <richard120310@...il.com>
To: jstultz@...gle.com
Cc: tglx@...utronix.de,
	sboyd@...nel.org,
	linux-kernel@...r.kernel.org,
	jserv@...s.ncku.edu.tw,
	skhan@...uxfoundation.org,
	linux-kernel-mentees@...ts.linux.dev,
	I Hsin Cheng <richard120310@...il.com>
Subject: [PATCH] clocksource: Utilize cpumask_next_wrap() to shrink code size

Simplify the procedure of CPU random selection under
"clocksource_verify_choose_cpus()" with "cpumask_next_wrap()". The
logic is still the same but with this change it can shrink the code size
by 18 bytes and increase readability.

$ ./scripts/bloat-o-meter vmlinux_old vmlinux_new
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-18 (-18)
Function                                     old     new   delta
clocksource_verify_percpu                   1064    1046     -18

Signed-off-by: I Hsin Cheng <richard120310@...il.com>
---
 kernel/time/clocksource.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index bb48498ebb5a..ab580873408b 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -343,9 +343,7 @@ static void clocksource_verify_choose_cpus(void)
 	 */
 	for (i = 1; i < n; i++) {
 		cpu = get_random_u32_below(nr_cpu_ids);
-		cpu = cpumask_next(cpu - 1, cpu_online_mask);
-		if (cpu >= nr_cpu_ids)
-			cpu = cpumask_first(cpu_online_mask);
+		cpu = cpumask_next_wrap(cpu - 1, cpu_online_mask);
 		if (!WARN_ON_ONCE(cpu >= nr_cpu_ids))
 			cpumask_set_cpu(cpu, &cpus_chosen);
 	}
-- 
2.43.0