On Mon, May 23, 2022 at 10:03:45AM -0600, Jens Axboe wrote: > clear_user() > 32 ~96MB/sec > 64 195MB/sec > 128 386MB/sec > 1k 2.7GB/sec > 4k 7.8GB/sec > 16k 14.8GB/sec > > copy_from_zero_page() > 32 ~96MB/sec > 64 193MB/sec > 128 383MB/sec > 1k 2.9GB/sec > 4k 9.8GB/sec > 16k 21.8GB/sec Just FYI, on x86, Samuel Neves proposed some nice clear_user() performance improvements that were forgotten about: https://lore.kernel.org/lkml/20210523180423.108087-1-sneves@xxxxxxxxx/ https://lore.kernel.org/lkml/Yk9yBcj78mpXOOLL@xxxxxxxxx/ Hoping somebody picks this up at some point... Jason
