linux-kernel - Re: [PATCH v13 01/11] bitops: Introduce the for_each_set

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Message-ID: <20190327064254.lwj7ew37mxphieco@wunner.de>
Date:   Wed, 27 Mar 2019 07:42:54 +0100
From:   Lukas Wunner <lukas@...ner.de>
To:     William Breathitt Gray <vilhelm.gray@...il.com>
Cc:     linus.walleij@...aro.org, bgolaszewski@...libre.com,
        akpm@...ux-foundation.org, linux-gpio@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-kernel@...r.kernel.org,
        andriy.shevchenko@...ux.intel.com, linux@...musvillemoes.dk,
        yamada.masahiro@...ionext.com,
        linux-arm-kernel@...ts.infradead.org, linux-pm@...r.kernel.org,
        geert@...ux-m68k.org, preid@...ctromag.com.au,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        Arnd Bergmann <arnd@...db.de>
Subject: Re: [PATCH v13 01/11] bitops: Introduce the for_each_set_clump8 macro

On Wed, Mar 27, 2019 at 01:58:45PM +0900, William Breathitt Gray wrote:
> This macro iterates for each 8-bit group of bits (clump) with set bits,
> within a bitmap memory region. For each iteration, "start" is set to the
> bit offset of the found clump, while the respective clump value is
> stored to the location pointed by "clump". Additionally, the
> bitmap_get_value8 and bitmap_set_value8 functions are introduced to
> respectively get and set an 8-bit value in a bitmap memory region.

I would have preferred static inlines for bitmap_get_value8(),
bitmap_set_value8() and find_next_clump8() to make this as fast
as possible in the callers because I've personally worked with
an industrial application where the GPIO pins of a 74x164 are
written every 250 usec.

But apart from that I like this series a lot, thanks for working on it.

Lukas