Messages in this thread Patch in this message | | | From | Xiao Wang <> | Subject | [PATCH] riscv: uaccess: Relax the threshold for fast path | Date | Wed, 13 Mar 2024 17:19:29 +0800 |
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The bytes copy for unaligned head would cover at most SZREG-1 bytes, so it's better to set the threshold as >= (SZREG-1 + word_copy stride size) which equals to 9*SZREG-1.
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com> --- arch/riscv/lib/uaccess.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index bc22c078aba8..2e665f8f8fcc 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -44,7 +44,7 @@ SYM_FUNC_START(fallback_scalar_usercopy) * Use byte copy only if too small. * SZREG holds 4 for RV32 and 8 for RV64 */ - li a3, 9*SZREG /* size must be larger than size in word_copy */ + li a3, 9*SZREG-1 /* size must >= (word_copy stride + SZREG-1) */ bltu a2, a3, .Lbyte_copy_tail /* -- 2.25.1
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