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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-09-06 21:48:46 +0200
committerAndrew Morton <akpm@linux-foundation.org>2022-09-27 04:46:15 +0200
commit2e3af1db174423e0fb75c7887251f168d8401424 (patch)
tree4b78e588cd3312b7451066b94b421b14a3894f2c /mm/mmap.c
parentmm: add VMA iterator (diff)
downloadlinux-2e3af1db174423e0fb75c7887251f168d8401424.tar.xz
linux-2e3af1db174423e0fb75c7887251f168d8401424.zip
mmap: use the VMA iterator in count_vma_pages_range()
This simplifies the implementation and is faster than using the linked list. Link: https://lkml.kernel.org/r/20220906194824.2110408-11-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Howells <dhowells@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c24
1 files changed, 7 insertions, 17 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 20718645d82f..f1b07751a1e4 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -629,29 +629,19 @@ 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 += PHYS_PFN(vm_end - vm_start);
}
return nr_pages;