Re: [PATCH v4 2/7] cpumask: Introduce for_each_cpu_andnot()

[Yury Norov <yury.norov@gmail.com>]

On Tue, Sep 27, 2022 at 05:45:04PM +0100, Valentin Schneider wrote:
> On 25/09/22 08:23, Yury Norov wrote:
> > On Fri, Sep 23, 2022 at 04:55:37PM +0100, Valentin Schneider wrote:
> >> +/**
> >> + * for_each_cpu_andnot - iterate over every cpu present in one mask, excluding
> >> + *			 those present in another.
> >> + * @cpu: the (optionally unsigned) integer iterator
> >> + * @mask1: the first cpumask pointer
> >> + * @mask2: the second cpumask pointer
> >> + *
> >> + * This saves a temporary CPU mask in many places.  It is equivalent to:
> >> + *	struct cpumask tmp;
> >> + *	cpumask_andnot(&tmp, &mask1, &mask2);
> >> + *	for_each_cpu(cpu, &tmp)
> >> + *		...
> >> + *
> >> + * After the loop, cpu is >= nr_cpu_ids.
> >> + */
> >> +#define for_each_cpu_andnot(cpu, mask1, mask2)				\
> >> +	for ((cpu) = -1;						\
> >> +		(cpu) = cpumask_next_andnot((cpu), (mask1), (mask2)),	\
> >> +		(cpu) < nr_cpu_ids;)
> >
> > This would raise cpumaks_check() warning at the very last iteration.
> > Because cpu is initialized insize the loop, you don't need to check it
> > at all. You can do it like this:
> >
> >  #define for_each_cpu_andnot(cpu, mask1, mask2)				\
> >          for_each_andnot_bit(...)
> >
> > Check this series for details (and please review).
> > https://lore.kernel.org/all/20220919210559.1509179-8-yury.norov@gmail.com/T/
> >
> 
> Thanks, I'll have a look.

Also, if you send first 4 patches as a separate series on top of
bitmap-for-next, I'll be able to include them in bitmap-for-next
and then in 6.1 pull-request.

Thanks,
Yury