linux-kernel - [PATCH 41/54] arch/x86: replace cpumask_weight with cpumask_weight

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Date:   Sun, 23 Jan 2022 10:39:12 -0800
From:   Yury Norov <yury.norov@...il.com>
To:     Yury Norov <yury.norov@...il.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michał Mirosław <mirq-linux@...e.qmqm.pl>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Peter Zijlstra <peterz@...radead.org>,
        David Laight <David.Laight@...lab.com>,
        Joe Perches <joe@...ches.com>, Dennis Zhou <dennis@...nel.org>,
        Emil Renner Berthing <kernel@...il.dk>,
        Nicholas Piggin <npiggin@...il.com>,
        Matti Vaittinen <matti.vaittinen@...rohmeurope.com>,
        Alexey Klimov <aklimov@...hat.com>,
        linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Tim Chen <tim.c.chen@...ux.intel.com>,
        Alison Schofield <alison.schofield@...el.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: [PATCH 41/54] arch/x86: replace cpumask_weight with cpumask_weight_eq where appropriate

smpboot code in somw places calls cpumask_weight() to compare the weight
of cpumask with a given number. We can do it more efficiently with
cpumask_weight_eq() because conditional cpumask_weight may stop traversing
the cpumask earlier, as soon as condition is met.

Signed-off-by: Yury Norov <yury.norov@...il.com>
---
 arch/x86/kernel/smpboot.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 617012f4619f..e851e9945eb5 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1608,7 +1608,7 @@ static void remove_siblinginfo(int cpu)
 		/*/
 		 * last thread sibling in this cpu core going down
 		 */
-		if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1)
+		if (cpumask_weight_eq(topology_sibling_cpumask(cpu), 1))
 			cpu_data(sibling).booted_cores--;
 	}
 
@@ -1617,7 +1617,7 @@ static void remove_siblinginfo(int cpu)
 
 	for_each_cpu(sibling, topology_sibling_cpumask(cpu)) {
 		cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
-		if (cpumask_weight(topology_sibling_cpumask(sibling)) == 1)
+		if (cpumask_weight_eq(topology_sibling_cpumask(sibling), 1))
 			cpu_data(sibling).smt_active = false;
 	}
 
-- 
2.30.2