riscv: enable HAVE_FAST_GUP if MMU
authorJisheng Zhang <jszhang@kernel.org>
Tue, 19 Dec 2023 17:50:46 +0000 (01:50 +0800)
committerPalmer Dabbelt <palmer@rivosinc.com>
Wed, 24 Jan 2024 23:55:56 +0000 (15:55 -0800)
commit3f910b7a522e064d7261f31a00d9c9dca31d902a
tree73bdd6bb36be0ca2a5dfb61e5f04fadec1833566
parent69be3fb111e73bd025ce6d2322371da5aa497c70
riscv: enable HAVE_FAST_GUP if MMU

Activate the fast gup for riscv mmu platforms. Here are some
GUP_FAST_BENCHMARK performance numbers:

Before the patch:
GUP_FAST_BENCHMARK: Time: get:53203 put:5085 us

After the patch:
GUP_FAST_BENCHMARK: Time: get:17711 put:5060 us

The get time is reduced by 66.7%! IOW, 3x get speed!

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231219175046.2496-5-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
arch/riscv/Kconfig
arch/riscv/include/asm/pgtable.h