public inbox for linux-kernel-mentees@lists.linux-foundation.org
 help / color / mirror / Atom feed
From: I Hsin Cheng <richard120310@gmail.com>
To: jstultz@google.com
Cc: tglx@linutronix.de, sboyd@kernel.org,
	linux-kernel@vger.kernel.org, jserv@ccns.ncku.edu.tw,
	skhan@linuxfoundation.org, linux-kernel-mentees@lists.linux.dev,
	I Hsin Cheng <richard120310@gmail.com>
Subject: [PATCH] clocksource: Utilize cpumask_next_wrap() to shrink code size
Date: Wed, 11 Jun 2025 18:45:06 +0800	[thread overview]
Message-ID: <20250611104506.2270561-1-richard120310@gmail.com> (raw)

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@gmail.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


             reply	other threads:[~2025-06-11 10:45 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-06-11 10:45 I Hsin Cheng [this message]
2025-06-11 18:35 ` [PATCH] clocksource: Utilize cpumask_next_wrap() to shrink code size John Stultz
2025-06-11 19:04   ` Yury Norov
2025-06-12  7:45     ` I Hsin Cheng
2025-06-12 15:33       ` Yury Norov
2025-06-13  5:13         ` Yury Norov
2025-06-13  5:25           ` I Hsin Cheng
2025-06-13  5:29           ` I Hsin Cheng

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250611104506.2270561-1-richard120310@gmail.com \
    --to=richard120310@gmail.com \
    --cc=jserv@ccns.ncku.edu.tw \
    --cc=jstultz@google.com \
    --cc=linux-kernel-mentees@lists.linux.dev \
    --cc=linux-kernel@vger.kernel.org \
    --cc=sboyd@kernel.org \
    --cc=skhan@linuxfoundation.org \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox