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This is not how things are working. So, should I ignore v2 now? Please allow your reviewers at least a few days before submitting any follow ups. On Thu, May 14, 2026 at 05:06:05PM +0800, Yi Sun wrote: > Based on Michał Nazarewicz's suggestion, > code optimization was performed on PATCH v1. > > Replacing find_next_bit() with find_last_bit_from() > can improve performance by an average of 50%. > The test results can be viewed in PATCH v1. > > > This section compares the performance of PATCH v2 and PATCH v3. > Test results show that PATCH v3 performs slightly better > than PATCH v2 in most cases. > When the number of 'goto again' loops is large, > PATCH v3's advantage becomes more apparent. > > > Test result: > cnt again_cnt v2_time(ns) v3_time(ns) time_ratio > test1 8 9 230 242 -5.2% > test2 8 1 75 76 around 0% > > test1 8 329 4452 4242 4.7% > test2 8 1 46 47 around 0% > > test1 32 10414 139015 132700 4.5% > test2 32 1 47 47 around 0% > > test1 128 2570 34163 32711 4.3% > test2 128 1 46 46 around 0% > > test1 1024 321 4293 4098 4.5% > test2 1024 6 126 122 3.2% > > test1 4096 81 1087 1046 3.8% > test2 4096 92 1656 1570 5.2% > > Test result explanation: > @test1: The bitmap is filled with random numbers, > so the bitmap is very messy. > @test2: Sparse bitmap. > > @cnt: The expected number of consecutive clear bits. > > @again_cnt: The number of 'goto again'. > > @v2_time(ns): The total time consumed by > bitmap_find_next_zero_area_off() when > using PATCH v2. > @v3_time(ns): The total time consumed by > bitmap_find_next_zero_area_off() when > using PATCH v3. > @time_ratio = (v2_time - v3_time) / v2_time. In v1 discussion, I asked you to turn your testing code into the addition to lib/find_bit_benchmark. Any reason to ignore that? Whatever you end up, it should not look how it looks now. I want to be able to compile the find_bit_benchmark, then run it before applying your series, and after that, and just compare 2 numbers for dense and 2 numbers for sparse bitmaps. Refer to e3783c805db29c8 as an example of how the tests look. > --- > v2: https://lore.kernel.org/all/20260514035644.4118050-1-yi.sun@unisoc.com > - Do not introduce find_last_bit_from(). > > v1: https://lore.kernel.org/all/20260512040659.2992142-1-yi.sun@unisoc.com > > > Yi Sun (2): > lib: bitmap: add find_last_bit_from() and _find_last_bit_from() > lib: bitmap: reduce the number of goto again in > bitmap_find_next_zero_area_off() > > include/linux/find.h | 33 +++++++++++++++++++++++++++++++++ > lib/bitmap.c | 2 +- > lib/find_bit.c | 22 ++++++++++++++++++++++ > 3 files changed, 56 insertions(+), 1 deletion(-) > > -- > 2.34.1