Hi:
On 2021/3/17 4:40, Peter Xu wrote:
> On Tue, Mar 16, 2021 at 08:40:02AM -0400, Miaohe Lin wrote:
>> +static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address)
>> +{
>> + /*
>> + * If the new address isn't hpage aligned and it could previously
>> + * contain an hugepage: check if we need to split an huge pmd.
>> + */
>> + if (address & ~HPAGE_PMD_MASK &&
>> + range_in_vma(vma, address & HPAGE_PMD_MASK,
>> + (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE))
>
> Since you're at it, maybe use ALIGN/ALIGN_DOWN too against HPAGE_PMD_SIZE?
>
Many thanks for reply. Sounds good. :) Do you mean this?
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index bff92dea5ab3..ae16a82da823 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2301,44 +2301,38 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
__split_huge_pmd(vma, pmd, address, freeze, page);
}
+static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address)
+{
+ /*
+ * If the new address isn't hpage aligned and it could previously
+ * contain an hugepage: check if we need to split an huge pmd.
+ */
+ if (!IS_ALIGNED(address, HPAGE_PMD_SIZE) &&
+ range_in_vma(vma, ALIGN_DOWN(address, HPAGE_PMD_SIZE),
+ ALIGN(address, HPAGE_PMD_SIZE)))
+ split_huge_pmd_address(vma, address, false, NULL);
+}
+
>> + split_huge_pmd_address(vma, address, false, NULL);
>> +}
>
