Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for shared mappings

From	"Kirill A. Shutemov" <kirill@shutemov.name>
Newsgroups	linux.kernel
Subject	Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for shared mappings
Date	2017-02-23 16:00 +0100
Message-ID	<te329-2EY-5@gated-at.bofh.it> (permalink)
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On Wed, Feb 22, 2017 at 04:15:07PM +0100, Andrea Arcangeli wrote:
> On Tue, Feb 21, 2017 at 04:25:45PM +0300, Kirill A. Shutemov wrote:
> > I think more strict vma_is_anonymous() is a good thing.
> > 
> > But I don't see a point introducing one more helper. Let's just make the
> > existing helper work better.
> 
> That would be simpler agreed. The point of having an "unsafe" faster
> version was only for code running in page fault context where the
> additional check is unnecessary.

Well, I don't think that the cost of additional check is significant here.
And we can bring ->vm_ops a bit closer to ->vm_flags to avoid potential
cache miss.

-- 
 Kirill A. Shutemov

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[PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for shared mappings Mike Kravetz <mike.kravetz@oracle.com> - 2017-02-15 22:50 +0100
  Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Andrea Arcangeli <aarcange@redhat.com> - 2017-02-16 19:50 +0100
    Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Mike Kravetz <mike.kravetz@oracle.com> - 2017-02-17 01:20 +0100
      Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Andrea Arcangeli <aarcange@redhat.com> - 2017-02-17 17:00 +0100
        Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Andrew Morton <akpm@linux-foundation.org> - 2017-02-17 21:20 +0100
          Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Andrea Arcangeli <aarcange@redhat.com> - 2017-02-17 22:00 +0100
            Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Andrew Morton <akpm@linux-foundation.org> - 2017-02-17 22:10 +0100
              Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Andrea Arcangeli <aarcange@redhat.com> - 2017-02-17 22:40 +0100
    Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-21 14:30 +0100
      Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings Andrea Arcangeli <aarcange@redhat.com> - 2017-02-22 16:20 +0100
        Re: [PATCH] userfaultfd: hugetlbfs: add UFFDIO_COPY support for  shared mappings "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-23 16:00 +0100

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