diff options
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 50 |
1 files changed, 29 insertions, 21 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index f1385c3b6c96..3d9f4abec17c 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5206,17 +5206,22 @@ void __unmap_hugepage_range_final(struct mmu_gather *tlb, __unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags); - /* - * Unlock and free the vma lock before releasing i_mmap_rwsem. When - * the vma_lock is freed, this makes the vma ineligible for pmd - * sharing. And, i_mmap_rwsem is required to set up pmd sharing. - * This is important as page tables for this unmapped range will - * be asynchrously deleted. If the page tables are shared, there - * will be issues when accessed by someone else. - */ - __hugetlb_vma_unlock_write_free(vma); - - i_mmap_unlock_write(vma->vm_file->f_mapping); + if (zap_flags & ZAP_FLAG_UNMAP) { /* final unmap */ + /* + * Unlock and free the vma lock before releasing i_mmap_rwsem. + * When the vma_lock is freed, this makes the vma ineligible + * for pmd sharing. And, i_mmap_rwsem is required to set up + * pmd sharing. This is important as page tables for this + * unmapped range will be asynchrously deleted. If the page + * tables are shared, there will be issues when accessed by + * someone else. + */ + __hugetlb_vma_unlock_write_free(vma); + i_mmap_unlock_write(vma->vm_file->f_mapping); + } else { + i_mmap_unlock_write(vma->vm_file->f_mapping); + hugetlb_vma_unlock_write(vma); + } } void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, @@ -6367,8 +6372,10 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, * tables. If the huge page is present, then the tail * pages must also be present. The ptl prevents the * head page and tail pages from being rearranged in - * any way. So this page must be available at this - * point, unless the page refcount overflowed: + * any way. As this is hugetlb, the pages will never + * be p2pdma or not longterm pinable. So this page + * must be available at this point, unless the page + * refcount overflowed: */ if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs, flags))) { @@ -7249,14 +7256,15 @@ retry: page = pte_page(pte) + ((address & ~huge_page_mask(h)) >> PAGE_SHIFT); /* - * try_grab_page() should always succeed here, because: a) we - * hold the pmd (ptl) lock, and b) we've just checked that the - * huge pmd (head) page is present in the page tables. The ptl - * prevents the head page and tail pages from being rearranged - * in any way. So this page must be available at this point, - * unless the page refcount overflowed: + * try_grab_page() should always be able to get the page here, + * because: a) we hold the pmd (ptl) lock, and b) we've just + * checked that the huge pmd (head) page is present in the + * page tables. The ptl prevents the head page and tail pages + * from being rearranged in any way. So this page must be + * available at this point, unless the page refcount + * overflowed: */ - if (WARN_ON_ONCE(!try_grab_page(page, flags))) { + if (try_grab_page(page, flags)) { page = NULL; goto out; } @@ -7294,7 +7302,7 @@ retry: pte = huge_ptep_get((pte_t *)pud); if (pte_present(pte)) { page = pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); - if (WARN_ON_ONCE(!try_grab_page(page, flags))) { + if (try_grab_page(page, flags)) { page = NULL; goto out; } |