[0/1] mm/hugetlb.c: teach follow_hugetlb_page() to handle FOLL_NOWAIT

Message

Andrea Arcangeli Jan. 9, 2019, 2:02 a.m. UTC

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(-)