Messages in this thread | | | Date | Fri, 3 Jan 2020 17:05:58 -0800 | From | Yury Norov <> | Subject | Re: [PATCH 3/3] lib/find_bit.c: uninline helper _find_next_bit() |
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On Fri, Jan 03, 2020 at 04:08:43PM -0800, Yury Norov wrote: > On Fri, Jan 03, 2020 at 01:46:07PM -0800, Joe Perches wrote: > > On Fri, 2020-01-03 at 12:28 -0800, Yury Norov wrote: > > > It saves 25% of .text for arm64, and more for BE architectures. > > > > This seems a rather misleading code size reduction description. > > > > Please detail the specific code sizes using "size lib/find_bit.o" > > before and after this change. > > Before: > $ size lib/find_bit.o > text data bss dec hex filename > 1012 56 0 1068 42c lib/find_bit.o > > After: > $ size lib/find_bit.o > text data bss dec hex filename > 776 56 0 832 340 lib/find_bit.o > > > Also, _find_next_bit is used 3 times, perhaps any code size > > increase is appropriate given likely reduced run time. > > Second patch of the series switches find_next_zero_bit_le() > and find_next_bit_le() to _find_next_bit(), so totally 5. > > Yury
> > perhaps any code size > > increase is appropriate given likely reduced run time.
I have a benchmark for the find_bit functions upstream, however, it cannot measure the overall performance degradation related to increased probability of cache eviction.
When I originally wrote _find_next_bit() in 2014, it was simpler and had 2 users. Now there are 5 of them, and I think it's good time to stop inlining _find_next_bit().
Yury
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