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SubjectRe: [PATCH 0/6] lib/find_bit: fast path for small bitmaps
On Fri, Jan 29, 2021 at 10:54 PM Yury Norov <yury.norov@gmail.com> wrote:
> On Fri, Jan 29, 2021 at 12:45 PM Yury Norov <yury.norov@gmail.com> wrote:
> >
> > Bitmap operations are much simpler and faster in case of small bitmaps, whicn
> > fit into a single word. In linux/bitmap.h we have a machinery that allows
> > compiler to replace actual function call with a few instructions if bitmaps
> > passed into the function is small and its size is known at compile time.
> >
> > find_*_bit() API lacks this functionality; despite users will benefit from it
> > a lot. One important example is cpumask subsystem, when NR_CPUS <= BITS_PER_LONG.
> > In the very best case, the compiler may replace a find_*_bit() call for such a
> > bitmap with a single ffs or ffz instruction.
> >
> > Tools is synchronized with new implementation where needed.
>
> Sorry for the broken enumeration . If it's too confusing, please let me know
> and I'll resend.

Yeah, please resend with a bumped version and respective changelog.

--
With Best Regards,
Andy Shevchenko

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