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From: Yury Norov <yury.norov@gmail.com>
To: linux-kernel@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Paul E. McKenney" <paulmck@kernel.org>,
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	Frederic Weisbecker <frederic@kernel.org>,
	Imran Khan <imran.f.khan@oracle.com>,
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	Valentin Schneider <vschneid@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Waiman Long <longman@redhat.com>,
	Yury Norov <yury.norov@gmail.com>,
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	cgroups@vger.kernel.org
Subject: [PATCH 1/6] smp: optimize smp_call_function_many_cond()
Date: Mon, 13 May 2024 15:01:41 -0700
Message-Id: <20240513220146.1461457-2-yury.norov@gmail.com>
In-Reply-To: <20240513220146.1461457-1-yury.norov@gmail.com>
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The function may be called with mask == cpu_online_mask, and in this
case we can use a cheaper cpumask_cooy() instead of cpumask_and().

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 kernel/smp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index f085ebcdf9e7..6f41214a1b54 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -798,7 +798,10 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
 
 	if (run_remote) {
 		cfd = this_cpu_ptr(&cfd_data);
-		cpumask_and(cfd->cpumask, mask, cpu_online_mask);
+		if (mask == cpu_online_mask)
+			cpumask_copy(cfd->cpumask, mask);
+		else
+			cpumask_and(cfd->cpumask, mask, cpu_online_mask);
 		__cpumask_clear_cpu(this_cpu, cfd->cpumask);
 
 		cpumask_clear(cfd->cpumask_ipi);
-- 
2.40.1