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References: <20220711044711.466822-1-yury.norov@gmail.com>
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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Mon, 11 Jul 2022 10:55:08 +0200
Message-ID: <CAHp75Vf8EhRYWdQN6Oc79GzWCvo-sRJDvy7_Aek_Z63GCu2dMQ@mail.gmail.com>
Subject: Re: [PATCH v2 0/5] lib/find: add find_nth_bit()
To:     Yury Norov <yury.norov@gmail.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Alexander Lobakin <alexandr.lobakin@intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Arnd Bergmann <arnd@arndb.de>, David Gow <davidgow@google.com>,
        Eric Dumazet <edumazet@google.com>,
        Isabella Basso <isabbasso@riseup.net>,
        Kees Cook <keescook@chromium.org>,
        Keith Busch <kbusch@kernel.org>,
        Kumar Kartikeya Dwivedi <memxor@gmail.com>,
        Marco Elver <elver@google.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Steven Rostedt <rostedt@goodmis.org>,
        =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= <toke@redhat.com>
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On Mon, Jul 11, 2022 at 6:51 AM Yury Norov <yury.norov@gmail.com> wrote:
>
> Kernel lacks for a function that searches for Nth bit in a bitmap.
> Usually people do it like this:
>         for_each_set_bit(bit, mask, size)
>                 if (--n == 0)
>                         return bit;
>
> Which is not so elegant, and very slow.
>
> This series adds fast routines for this task, and applies them where
> appropriate.
>
> While here, move thin wrappers around find_bit() in nodemask.c to a
> corresponding header, and because nodemask.c is empty after that,
> remove it.
>
> v1: https://lore.kernel.org/lkml/20220706182300.70862-4-yury.norov@gmail.com/T/
> v2: - count Nth bit from 0 (was 1);
>     - use 'invert' trick in _find_nth_bit(), as in _find_next_bit();
>     - cleanup comments;
>     - fns() is kept inline - looking at __ffs() generic implementation,
>       I decided to keep it untouched.

Two observations:
1) your patches are not versioned (hint: use `git format-patch
--thread -vX --cover-letter ...`, where X is a version you want to
give);
2) fns() is not good abbreviation, because among ffs (First) and fls
(Last), fns would be read as Next, which is misleading, I'm not sure
fnths(), which is correct, is good for readers.

-- 
With Best Regards,
Andy Shevchenko