Re: [PATCH 38/54] arch/mips: replace cpumask_weight with cpumask_weight_{eq, ...} where appropriate

From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To: Yury Norov <yury.norov@gmail.com>
Cc: "Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"David Laight" <David.Laight@aculab.com>,
	"Joe Perches" <joe@perches.com>,
	"Dennis Zhou" <dennis@kernel.org>,
	"Emil Renner Berthing" <kernel@esmil.dk>,
	"Nicholas Piggin" <npiggin@gmail.com>,
	"Matti Vaittinen" <matti.vaittinen@fi.rohmeurope.com>,
	"Alexey Klimov" <aklimov@redhat.com>,
	linux-kernel@vger.kernel.org,
	"Mark Rutland" <mark.rutland@arm.com>,
	"Marc Zyngier" <maz@kernel.org>,
	linux-mips@vger.kernel.org
Subject: Re: [PATCH 38/54] arch/mips: replace cpumask_weight with cpumask_weight_{eq, ...} where appropriate
Date: Tue, 25 Jan 2022 20:05:31 +0100	[thread overview]
Message-ID: <20220125190531.GA31998@alpha.franken.de> (raw)
In-Reply-To: <20220123183925.1052919-39-yury.norov@gmail.com>

On Sun, Jan 23, 2022 at 10:39:09AM -0800, Yury Norov wrote:
> Mips code uses 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@gmail.com>
> ---
>  arch/mips/cavium-octeon/octeon-irq.c | 4 ++--
>  arch/mips/kernel/crash.c             | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/mips/cavium-octeon/octeon-irq.c b/arch/mips/cavium-octeon/octeon-irq.c
> index 844f882096e6..914871f15fb7 100644
> --- a/arch/mips/cavium-octeon/octeon-irq.c
> +++ b/arch/mips/cavium-octeon/octeon-irq.c
> @@ -763,7 +763,7 @@ static void octeon_irq_cpu_offline_ciu(struct irq_data *data)
>  	if (!cpumask_test_cpu(cpu, mask))
>  		return;
>  
> -	if (cpumask_weight(mask) > 1) {
> +	if (cpumask_weight_gt(mask, 1)) {
>  		/*
>  		 * It has multi CPU affinity, just remove this CPU
>  		 * from the affinity set.
> @@ -795,7 +795,7 @@ static int octeon_irq_ciu_set_affinity(struct irq_data *data,
>  	 * This removes the need to do locking in the .ack/.eoi
>  	 * functions.
>  	 */
> -	if (cpumask_weight(dest) != 1)
> +	if (!cpumask_weight_eq(dest, 1))
>  		return -EINVAL;
>  
>  	if (!enable_one)
> diff --git a/arch/mips/kernel/crash.c b/arch/mips/kernel/crash.c
> index 81845ba04835..5b690d52491f 100644
> --- a/arch/mips/kernel/crash.c
> +++ b/arch/mips/kernel/crash.c
> @@ -72,7 +72,7 @@ static void crash_kexec_prepare_cpus(void)
>  	 */
>  	pr_emerg("Sending IPI to other cpus...\n");
>  	msecs = 10000;
> -	while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
> +	while (cpumask_weight_lt(&cpus_in_crash, ncpus) && (--msecs > 0)) {
>  		cpu_relax();
>  		mdelay(1);
>  	}
> -- 
> 2.30.2

Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

-- 
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