diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hugetlb.c | 49 |
1 files changed, 28 insertions, 21 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d4fc5db6bc32..cf6653879bb4 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4787,6 +4787,20 @@ out_release_nounlock: goto out; } +static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma, + int refs, struct page **pages, + struct vm_area_struct **vmas) +{ + int nr; + + for (nr = 0; nr < refs; nr++) { + if (likely(pages)) + pages[nr] = mem_map_offset(page, nr); + if (vmas) + vmas[nr] = vma; + } +} + long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page **pages, struct vm_area_struct **vmas, unsigned long *position, unsigned long *nr_pages, @@ -4916,28 +4930,16 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, continue; } - refs = 0; + refs = min3(pages_per_huge_page(h) - pfn_offset, + (vma->vm_end - vaddr) >> PAGE_SHIFT, remainder); -same_page: - if (pages) - pages[i] = mem_map_offset(page, pfn_offset); + if (pages || vmas) + record_subpages_vmas(mem_map_offset(page, pfn_offset), + vma, refs, + likely(pages) ? pages + i : NULL, + vmas ? vmas + i : NULL); - if (vmas) - vmas[i] = vma; - - vaddr += PAGE_SIZE; - ++pfn_offset; - --remainder; - ++i; - ++refs; - if (vaddr < vma->vm_end && remainder && - pfn_offset < pages_per_huge_page(h)) { - /* - * We use pfn_offset to avoid touching the pageframes - * of this compound page. - */ - goto same_page; - } else if (pages) { + if (pages) { /* * try_grab_compound_head() should always succeed here, * because: a) we hold the ptl lock, and b) we've just @@ -4948,7 +4950,7 @@ same_page: * any way. So this page must be available at this * point, unless the page refcount overflowed: */ - if (WARN_ON_ONCE(!try_grab_compound_head(pages[i-1], + if (WARN_ON_ONCE(!try_grab_compound_head(pages[i], refs, flags))) { spin_unlock(ptl); @@ -4957,6 +4959,11 @@ same_page: break; } } + + vaddr += (refs << PAGE_SHIFT); + remainder -= refs; + i += refs; + spin_unlock(ptl); } *nr_pages = remainder; |