From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dennis Zhou <dennis@kernel.org>
Subject: Re: [PATCH 7/9] lib/cpumask: add
 num_{possible,present,active}_cpus_{eq,gt,le}
Date: Sun, 28 Nov 2021 12:54:00 -0500
Message-ID: <YaPCOPqpI/oKrTXl@fedora>
References: <20211128035704.270739-1-yury.norov@gmail.com>
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 <20211128174320.GA304543@lapt>
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To: Yury Norov <yury.norov@gmail.com>
Cc: Joe Perches <joe@perches.com>, linux-kernel@vger.kernel.org, "James E.J. Bottomley" <jejb@linux.ibm.com>, "Martin K. Petersen" <martin.petersen@oracle.com>, "Paul E. McKenney" <paulmck@kernel.org>, "Rafael J. Wysocki" <rafael@kernel.org>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Alexey Klimov <aklimov@redhat.com>, Amitkumar Karwar <amitkarwar@gmail.com>, Andi Kleen <ak@linux.intel.com>, Andrew Lunn <andrew@lunn.ch>, Andrew Morton <akpm@linux-foundation.org>, Andy Gross <agross@kernel.org>, Andy Lutomirski <luto@kernel.org>, Andy Shevchenko <andy@infradead.org>, Anup Patel <anup.patel@wdc.com>, Ard Biesheuvel <ardb@kernel.org>, Arnaldo Carvalho de Melo <acme@kernel.org>, Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>, Ca

Hello,

On Sun, Nov 28, 2021 at 09:43:20AM -0800, Yury Norov wrote:
> On Sun, Nov 28, 2021 at 09:07:52AM -0800, Joe Perches wrote:
> > On Sat, 2021-11-27 at 19:57 -0800, Yury Norov wrote:
> > > Add num_{possible,present,active}_cpus_{eq,gt,le} and replace num_*_cpus()
> > > with one of new functions where appropriate. This allows num_*_cpus_*()
> > > to return earlier depending on the condition.
> > []
> > > diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c
> > []
> > > @@ -103,7 +103,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
> > >  	 * if platform didn't set the present map already, do it now
> > >  	 * boot cpu is set to present already by init/main.c
> > >  	 */
> > > -	if (num_present_cpus() <= 1)
> > > +	if (num_present_cpus_le(2))
> > >  		init_cpu_present(cpu_possible_mask);
> > 
> > ?  is this supposed to be 2 or 1
> 
> X <= 1 is the equivalent of X < 2.
> 
> > > diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c
> > []
> > > @@ -593,7 +593,7 @@ static int __init pcc_cpufreq_init(void)
> > >  		return ret;
> > >  	}
> > >  
> > > -	if (num_present_cpus() > 4) {
> > > +	if (num_present_cpus_gt(4)) {
> > >  		pcc_cpufreq_driver.flags |= CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
> > >  		pr_err("%s: Too many CPUs, dynamic performance scaling disabled\n",
> > >  		       __func__);
> > 
> > It looks as if the present variants should be using the same values
> > so the _le test above with 1 changed to 2 looks odd.
>  

I think the confusion comes from le meaning less than rather than lt.
Given the general convention of: lt (<), le (<=), eg (=), ge (>=),
gt (>), I'd consider renaming your le to lt.

Thanks,
Dennis