Re: [PATCH v6 1/5] lib/bitmap: add bitmap_{read,write}()

[Alexander Potapenko]

On Tue, Oct 10, 2023 at 1:03 PM Rasmus Villemoes
<linux@xxxxxxxxxxxxxxxxxx> wrote:
>
> On 10/10/2023 11.17, Alexander Potapenko wrote:
>
> >> 'behaves similarly' sounds like an understatement. I think, it behaves
> >> much faster because it can assign up to 64 bits at once, not mentioning
> >> the pressure on cache lines traffic.
> >
> > My intent was to describe the visible behavior, of course the
> > generated code is better, and the number of memory accesses lower.
> >
> > How about the following description:
> >
> >  * The result of bitmap_write() is similar to @nbits calls of assign_bit(), i.e.
> >  * bits beyond @nbits are ignored:
> >  *
> >  *   for (bit = 0; bit < nbits; bit++)
> >  *           assign_bit(start + bit, bitmap, val & BIT(bit));
> >
> > ?
>
> C programmers should know the meaning of the term "as-if". Perhaps use
> that. Smth like "bitmap_write() behaves as-if implemented as @nbits
> calls of __assign_bit()".

Good idea, I'll go with this one.
Thank you!