On Tue, Feb 16, 2021 at 11:14:23AM +0200, Andy Shevchenko wrote: > On Mon, Feb 15, 2021 at 01:30:44PM -0800, Yury Norov wrote: > > [add David Laight <David.Laight@xxxxxxxxxx> ] > > > > On Sat, Jan 30, 2021 at 11:17:11AM -0800, Yury Norov wrote: > > > Bitmap operations are much simpler and faster in case of small bitmaps > > > which 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 are small and their 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. > > > > > > v1: https://www.spinics.net/lists/kernel/msg3804727.html > > > v2: - employ GENMASK() for bitmaps; > > > - unify find_bit inliners in; > > > - address comments to v1; > > > > Comments so far: > > - increased image size (patch #8) - addressed by introducing > > CONFIG_FAST_PATH; > > > - split tools and kernel parts - not clear why it's better. > > Because tools are user space programs and sometimes may not follow kernel > specifics, so they are different logically and changes should be separated. In this specific case tools follow kernel well. Nevertheless, if you think it's a blocker for the series, I can split. What option for tools is better for you - doubling the number of patches or squashing everything in a patch bomb?
