On Fri, Jan 29, 2021 at 10:54 PM Yury Norov <yury.norov@xxxxxxxxx> wrote:
On Fri, Jan 29, 2021 at 12:45 PM Yury Norov <yury.norov@xxxxxxxxx> 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
