Messages in this thread Patch in this message | | | From | Baolin Wang <> | Subject | [PATCH v2 4/5] mm/hugetlb: use PMD page lock to protect CONT-PTE entries | Date | Tue, 23 Aug 2022 15:50:04 +0800 |
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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@linux.alibaba.com> --- 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
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