[PATCH v4 08/66] mmap: Use the VMA iterator in count_vma_pages_range()
From: Liam Howlett <hidden>
Date: 2021-12-01 14:33:42
Also in:
lkml
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
From: "Matthew Wilcox (Oracle)" <willy@infradead.org> This simplifies the implementation and is faster than using the linked list. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- mm/mmap.c | 24 +++++++----------------- 1 file changed, 7 insertions(+), 17 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 9fee6e6b276f..de78fc0ce809 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -669,29 +669,19 @@ munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len, return 0; } + static unsigned long count_vma_pages_range(struct mm_struct *mm, unsigned long addr, unsigned long end) { - unsigned long nr_pages = 0; + VMA_ITERATOR(vmi, mm, addr); struct vm_area_struct *vma; + unsigned long nr_pages = 0; - /* Find first overlapping mapping */ - vma = find_vma_intersection(mm, addr, end); - if (!vma) - return 0; - - nr_pages = (min(end, vma->vm_end) - - max(addr, vma->vm_start)) >> PAGE_SHIFT; - - /* Iterate over the rest of the overlaps */ - for (vma = vma->vm_next; vma; vma = vma->vm_next) { - unsigned long overlap_len; - - if (vma->vm_start > end) - break; + for_each_vma_range(vmi, vma, end) { + unsigned long vm_start = max(addr, vma->vm_start); + unsigned long vm_end = min(end, vma->vm_end); - overlap_len = min(end, vma->vm_end) - vma->vm_start; - nr_pages += overlap_len >> PAGE_SHIFT; + nr_pages += (vm_end - vm_start) / PAGE_SIZE; } return nr_pages;
--
2.30.2