Considering the pmd entries of a CONT-PMD hugetlb can not span on
multiple PMDs, we can change to use the PMD page lock, which can
be much finer grain that lock in the mm.
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3a96f67..d4803a89 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -892,9 +892,17 @@ static inline gfp_t htlb_modify_alloc_mask(struct hstate *h, gfp_t gfp_mask)
static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
struct mm_struct *mm, pte_t *pte)
{
- VM_BUG_ON(huge_page_size(h) == PAGE_SIZE);
+ unsigned long hp_size = huge_page_size(h);
- if (huge_page_size(h) == PMD_SIZE) {
+ VM_BUG_ON(hp_size == PAGE_SIZE);
+
+ /*
+ * Considering CONT-PMD size hugetlb, since the CONT-PMD entry
+ * can not span multiple PMDs, then we can use the fine grained
+ * PMD page lock.
+ */
+ if (hp_size == PMD_SIZE ||
+ (hp_size > PMD_SIZE && hp_size < PUD_SIZE)) {
return pmd_lockptr(mm, (pmd_t *) pte);
} else if (huge_page_size(h) < PMD_SIZE) {
unsigned long mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1);
--
1.8.3.1
