On 5/23/22 9:55 AM, Jens Axboe wrote: > Was going to test on aarch64 next... Just for completeness, before diving into that thread. On aarch64, 16k native page size, but running in a vm with 4k page size: 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 Tad slower on <= 128 bytes, 1k a bit faster, and substantially faster above that. Eg same logic would be sane on aarch64 as it is on x86-64, use copy_from_zero_page at > 128 bytes. -- Jens Axboe
