Re: [PATCH 0/1] __asm_copy_to-from_user: Reduce more byte_copy
From: Akira Tsukamoto
Date: Thu Aug 12 2021 - 07:01:37 EST
Hi Guenter, Geert and Qiu,
Would you mind testing this patch?
On 7/30/2021 10:50 PM, Akira Tsukamoto wrote:
> Adding none unrolling word_copy, which is used if the size is smaller
> than 9*SZREG.
> This patch is based on Palmer's past comment.
>> My guess is that some workloads will want some smaller unrolling factors,
> It will reduce the number of slow byte_copy being used when the
> size is small.
> Have tested on qemu rv32, qemu rv64 and beaglev beta board.
> In the future, I am planning to convert uaccess.S to inline assembly
> in .c file. Then it will be easier to optimize on both in-order core and
> out-of-order core with #ifdef macro in c.
> Akira Tsukamoto (1):
> riscv: __asm_copy_to-from_user: Improve using word copy if size <
> arch/riscv/lib/uaccess.S | 46 ++++++++++++++++++++++++++++++++++++----
> 1 file changed, 42 insertions(+), 4 deletions(-)