Messages in this thread | | | From | Andy Shevchenko <> | Date | Mon, 11 Jul 2022 10:55:08 +0200 | Subject | Re: [PATCH v2 0/5] lib/find: add find_nth_bit() |
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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
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