Re: [PATCH v2 1/5] bitops: Introduce find_next_andnot_bit()

From: Valentin Schneider
Date: Thu Aug 18 2022 - 12:27:04 EST


On 18/08/22 10:08, Steven Rostedt wrote:
> On Wed, 17 Aug 2022 18:58:08 +0100
> Valentin Schneider <vschneid@xxxxxxxxxx> wrote:
>
>> +#ifndef find_next_andnot_bit
>> +/**
>> + * find_next_andnot_bit - find the next set bit in one memory region
>> + * but not in the other
>> + * @addr1: The first address to base the search on
>> + * @addr2: The second address to base the search on
>> + * @size: The bitmap size in bits
>> + * @offset: The bitnumber to start searching at
>> + *
>> + * Returns the bit number for the next set bit
>> + * If no bits are set, returns @size.
>
> Can we make the above documentation more descriptive. Because I read this
> three times, and I still have no idea what it does.
>
> The tag line sounds like the nursery song "One of these things is not like
> the others".
>

How about:

find the next set bit in ((first region) AND NOT(second region))

Or

find the next set bit in (*addr1 & ~*addr2)

?

> -- Steve