Messages in this thread | | | Date | Tue, 21 Jun 2022 23:13:31 +0200 | Subject | Re: [PATCH v10 10/69] mmap: use the VMA iterator in count_vma_pages_range() | From | David Hildenbrand <> |
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On 21.06.22 22:46, Liam Howlett wrote: > From: "Matthew Wilcox (Oracle)" <willy@infradead.org> > > This simplifies the implementation and is faster than using the linked > list. > > Link: https://lkml.kernel.org/r/20220504010716.661115-12-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> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: David Howells <dhowells@redhat.com> > Cc: SeongJae Park <sj@kernel.org> > Cc: Will Deacon <will@kernel.org> > Cc: Davidlohr Bueso <dave@stgolabs.net> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > --- > mm/mmap.c | 24 +++++++----------------- > 1 file changed, 7 insertions(+), 17 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 6be7833c781b..d7e6baa2f40f 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -675,29 +675,19 @@ 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);
I thought using max_t and min_t was the latest advisory. I might be wrong and simply kept doing it that way ;)
> > - overlap_len = min(end, vma->vm_end) - vma->vm_start; > - nr_pages += overlap_len >> PAGE_SHIFT; > + nr_pages += (vm_end - vm_start) / PAGE_SIZE;
PHYS_PFN(vm_end - vm_start)
> } > > return nr_pages;
Reviewed-by: David Hildenbrand <david@redhat.com>
-- Thanks,
David / dhildenb
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