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From:   Andrea Arcangeli <aarcange@redhat.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Mike Rapoport <rppt@linux.vnet.ibm.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Peter Xu <peterx@redhat.com>,
        "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Subject: [PATCH 0/1] mm/hugetlb.c: teach follow_hugetlb_page() to handle FOLL_NOWAIT
Date:   Tue,  8 Jan 2019 21:02:02 -0500
Message-Id: <20190109020203.26669-1-aarcange@redhat.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Hello,

this fixes a regression that resurfaced in hugetlbfs code after we
fixed it for the core VM a few months ago. This is only reproducible
doing postcopy live migration of KVM (the only user of FOLL_NOWAIT) if
backed by hugetlbfs memory. It's unrelated to userfaultfd, but
userfaultfd reproduces it easily because it's an heavy user of
VM_FAULT_RETRY retvals.

Thanks,
Andrea

Andrea Arcangeli (1):
  mm/hugetlb.c: teach follow_hugetlb_page() to handle FOLL_NOWAIT

 mm/hugetlb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)