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Date:   Thu, 7 Dec 2023 14:16:47 -0800
From:   Yury Norov <yury.norov@gmail.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Thomas Gleixner <tglx@linutronix.de>, linux-kernel@vger.kernel.org,
        Ming Lei <ming.lei@redhat.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: Re: [PATCH v2 1/6] cpumask: introduce for_each_cpu_and_from()
Message-ID: <ZXJET4HjL+tpBwze@yury-ThinkPad>
References: <20231207203900.859776-1-yury.norov@gmail.com>
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 <20231207134156.494973b8d8aa7e1aac4891d6@linux-foundation.org>
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On Thu, Dec 07, 2023 at 01:41:56PM -0800, Andrew Morton wrote:
> On Thu,  7 Dec 2023 12:38:55 -0800 Yury Norov <yury.norov@gmail.com> wrote:
> 
> > Similarly to for_each_cpu_and(), introduce a for_each_cpu_and_from(),
> > which is handy when it's needed to traverse 2 cpumasks or bitmaps,
> > starting from a given position.
> 
> A naming question:
> 
> > --- a/include/linux/cpumask.h
> > +++ b/include/linux/cpumask.h
> > @@ -332,6 +332,17 @@ unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int sta
> >  #define for_each_cpu_and(cpu, mask1, mask2)				\
> >  	for_each_and_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits)
> >  
> > +/**
> > + * for_each_cpu_and_from - iterate over every cpu in both masks starting from a given cpu
> > + * @cpu: the (optionally unsigned) integer iterator
> > + * @mask1: the first cpumask pointer
> > + * @mask2: the second cpumask pointer
> > + *
> > + * After the loop, cpu is >= nr_cpu_ids.
> > + */
> > +#define for_each_cpu_and_from(cpu, mask1, mask2)				\
> > +	for_each_and_bit_from(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits)
> 
> Shouldn't this be for_each_and_cpu_from()?  That seems more consistent
> and makes a little more sense given what the iterator does.

Maybe it should... But we already have some iterators with this type
of naming: for_each_cpu_and, for_each_cpu_andnot, for_each_cpu_or.

This naming style goes quite long back in the history. Corresponding
bitmap iterators have better naming although...