From 1e6084d5c433b142b18d57694a6ab555ca6bb8cc Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Mon, 17 Nov 2025 21:19:27 -0700 Subject: [PATCH] riscv: mm: pmdp_huge_get_and_clear(): avoid atomic ops when !CONFIG_SMP When !CONFIG_SMP, there's no need for atomic operations in pmdp_huge_get_and_clear(), so, similar to what x86 does, let's not use atomics in this case. See also commit 546e42c8c6d94 ("riscv: Use an atomic xchg in pudp_huge_get_and_clear()"). Cc: Alexandre Ghiti Signed-off-by: Paul Walmsley --- arch/riscv/include/asm/pgtable.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 8bd36ac842eba..1df8a6adb407e 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -997,7 +997,13 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long address, pmd_t *pmdp) { +#ifdef CONFIG_SMP pmd_t pmd = __pmd(atomic_long_xchg((atomic_long_t *)pmdp, 0)); +#else + pmd_t pmd = *pmdp; + + pmd_clear(pmdp); +#endif page_table_check_pmd_clear(mm, pmd); -- 2.47.3