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Subject[PATCH] riscv: uaccess: Relax the threshold for fast path
Date
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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