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([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-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 = 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