Messages in this thread | | | From | Yury Norov <> | Date | Tue, 12 Jul 2022 09:26:10 -0700 | Subject | Re: [PATCH v2 0/5] lib/find: add find_nth_bit() |
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On Mon, Jul 11, 2022 at 1:55 AM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > 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);
OK
> 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.
I agree that fns() may be confusing, but fnths() is even worse to me. I expect that it will be mostly used indirectly via find_nth_bit(), and will not create a lot of confusion for users.
Thanks, Yury
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