From nobody Sat Oct 11 04:24:49 2025 Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83BA1289E01 for ; Wed, 11 Jun 2025 10:45:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749638715; cv=none; b=pK4EOB4xFS6+0s6eVsA1yhmYHmIw27/avQ7VNaIg4VvVJJiLv+DoaXv3BREL+uRIlqcOGjugqweeWGkKWsiHkCIM6hEsJNRJIZeS2tYPGd3EqNgevkkG3BX3VmmVvTN+xKiez2WjoJpLGtCVv/VZhuu0rvMdbAwTEyauhzAhzuU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749638715; c=relaxed/simple; bh=r6AzIemY8jhRgeGmeH2XDBuKf9B22/TpiN2MBecEYM0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=GK9RW06iz80mt28+qlf9YgkqmfIjVwmN9A1g8NjkOK1kF+E1c/b17MGFR8SDpFH3+QGVML/zYPucvwJUsjGduk+PPqgicA/Tgl5i6PR07F57Un99IOmsQ8Kg21LZK/76XKobUwrmv3a4U+2us2RMD5PWz2W6JOlutl+HBwqOJE0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=kziz+Oic; arc=none smtp.client-ip=209.85.210.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kziz+Oic" Received: by mail-pf1-f175.google.com with SMTP id d2e1a72fcca58-74877ac9d42so79865b3a.1 for ; Wed, 11 Jun 2025 03:45:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1749638712; x=1750243512; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=i+hXt20KOnpHxPZlTruLIdjQ7iUCgl0yVHEwobe4r+s=; b=kziz+Oic31W3XX5A2KKbdCUWySfSon8KRw/3nT/eEgsDDB0lxfoUbQZfO2SBZMyjS2 fKr+zGPx++sf6TOxAPn7dRSfub5W+0QnrR9t/A8rFuUJSLzn5I8VDqg7e9D8olHRotHR VyghsN5EVsl5cDnvjGbyX+Vvh8ANoeNJuvvA9RgxmwpzSF4LrbMyGD5Zohh+sPMtxPUS 346oFcmQfDPhUQqqyA1wJ5tI8ycX3ha2OdSizUC9U1dDIAUQN4YDhsrz1u0bstVj3F3n Z1wVlw4WxlcWX3WksRWpIYFM5Zj/brNlThjE+iMlwcPUoxLjEAm1hL+hcxO7dnsMP/JY aYCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749638712; x=1750243512; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=i+hXt20KOnpHxPZlTruLIdjQ7iUCgl0yVHEwobe4r+s=; b=F2h1osfdVBkK/9D0tkH+npzhfUj8Cpb4v3fUPHL9DCRWvsJGL3+lrUSipGLWnLh5KW A0vf8CqDuqAnnCYNXdBfMHuxvpN3PnnF3XCW5HK1inzVPm0kF9b2hM2k7o2lkVaLZYya yIGElO2rPAOEA1kY6Tjib8bSjFgRLRZ3z1BxWdLo4wkJH7GMYq+64h1es2K09MDLuviM 3Vs6ajgeyrhi+mvzpMIxXn7yZLXTO3aF5w7DOg8xw338VtFWbMEoS0yiUxL/ZuuoF3id 6VQ08G3xRneBYdrtuCGQCDM8Is3NzGJQh2a6mEjQx90cARSve7Zqjp7LDyUmUmO1L+d5 Uyeg== X-Forwarded-Encrypted: i=1; AJvYcCWVjmbbG4h9+JFFgM8hTw+rftMOuLG6L8fF628FXBOFrLMllfGsFsZX8mouRhBZV1JFsJJsHR7FsI2snjA=@vger.kernel.org X-Gm-Message-State: AOJu0YwWEQFhDERvQxU6sce2alYRAuxV4Gng9mPZQtFoW/DMUQ45aZe8 0EE+czWXRZ+KJ1Y2ZDK28whBWgZ/T0BmQTG+MdN4hRFCjKXbt8C2Pe5doqPOCpqg X-Gm-Gg: ASbGnctMo68+xanIAch+PXjcnlW7Irgy6TgBxO/1Qrab1FN1ZbhyYgpQfBMIt834cCH RCv7vhqgI7GJBMEobBnXoXks8rtaRNbVGCGoXOlH4mKZ10lY69sHAO3qCpaEaTFOXG2ekEFu/G8 KBimtCktyECaFE07MMOgZxQ4jQbx2BVYnTV5GFftKmaIJq7KZ9LbEZgYwe8h/lZSZ6beB8wquCO v3IHdQSK3T+bQr0j25m5YmuthewwjlDlQTwbaFYAIaWAWc/nhHaKHhuudOqmKgshO39obdY/5RR rMyeSU6bgRzO3bgtbE5mw799MVyKTsGNsMW5IJTQ4bJm3CF/Euw6sfBl3uFywJknpGadHawu0TJ qrXRMH2TGuMhnQksi X-Google-Smtp-Source: AGHT+IHaa70N8CkqnPXWc91UlgDo+p6GMS44gx+oso4/GpQPu/T3Sek0DJUNLJfLi0Wcarzi3fnvig== X-Received: by 2002:a05:6a21:4593:b0:21f:449e:f6df with SMTP id adf61e73a8af0-21f86746da6mr4732949637.41.1749638712361; Wed, 11 Jun 2025 03:45:12 -0700 (PDT) Received: from vaxr-ASUSPRO-D840MB-M840MB.. ([2001:288:7001:2703:52f2:ddbc:f858:ca43]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7482b0f2e77sm9099735b3a.176.2025.06.11.03.45.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Jun 2025 03:45:11 -0700 (PDT) From: I Hsin Cheng 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 Subject: [PATCH] clocksource: Utilize cpumask_next_wrap() to shrink code size Date: Wed, 11 Jun 2025 18:45:06 +0800 Message-ID: <20250611104506.2270561-1-richard120310@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 --- 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 =3D 1; i < n; i++) { cpu =3D get_random_u32_below(nr_cpu_ids); - cpu =3D cpumask_next(cpu - 1, cpu_online_mask); - if (cpu >=3D nr_cpu_ids) - cpu =3D cpumask_first(cpu_online_mask); + cpu =3D cpumask_next_wrap(cpu - 1, cpu_online_mask); if (!WARN_ON_ONCE(cpu >=3D nr_cpu_ids)) cpumask_set_cpu(cpu, &cpus_chosen); } --=20 2.43.0