Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 <alex@ghiti.fr>
Signed-off-by: Paul Walmsley <pjw@kernel.org>
+6
+6
arch/riscv/include/asm/pgtable.h
+6
arch/riscv/include/asm/pgtable.h
···
997
997
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
998
998
unsigned long address, pmd_t *pmdp)
999
999
{
1000
+
#ifdef CONFIG_SMP
1000
1001
pmd_t pmd = __pmd(atomic_long_xchg((atomic_long_t *)pmdp, 0));
1002
+
#else
1003
+
pmd_t pmd = *pmdp;
1004
+
1005
+
pmd_clear(pmdp);
1006
+
#endif
1001
1007
1002
1008
page_table_check_pmd_clear(mm, pmd);
1003
1009