| Date | Wed, 19 Jan 2022 18:39:16 +0100 | Subject | Re: [PATCH v4 50/66] mm/gup: Use maple tree navigation instead of linked list | From | Vlastimil Babka <> |
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On 12/1/21 15:30, Liam Howlett wrote: > From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Empty message.
> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> > --- > mm/gup.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/mm/gup.c b/mm/gup.c > index 2c51e9748a6a..60892e5df6a2 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -1570,7 +1570,6 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) > long ret = 0; > > end = start + len; > - > for (nstart = start; nstart < end; nstart = nend) { > /* > * We want to fault in pages for [nstart; end) address range. > @@ -1579,10 +1578,10 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) > if (!locked) { > locked = 1; > mmap_read_lock(mm); > - vma = find_vma(mm, nstart); > + vma = find_vma_intersection(mm, start, end);
Is it ok to use start instead of nstart? At least theoretically, populate_vma_page_range() called later can reset locked to 0, so !locked doesn't guarantee we are in the first iteration?
> } else if (nstart >= vma->vm_end) > - vma = vma->vm_next; > - if (!vma || vma->vm_start >= end) > + vma = find_vma(mm, vma->vm_end); > + if (!vma) > break; > /* > * Set [nstart; nend) to intersection of desired address
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