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Date:   Tue, 10 Oct 2023 13:03:21 +0200
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Subject: Re: [PATCH v6 1/5] lib/bitmap: add bitmap_{read,write}()
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To:     Alexander Potapenko <glider@google.com>,
        Yury Norov <yury.norov@gmail.com>
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        syednwaris@gmail.com, william.gray@linaro.org,
        Arnd Bergmann <arnd@arndb.de>
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From:   Rasmus Villemoes <linux@rasmusvillemoes.dk>
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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()".

Rasmus