[PATCHv2 0/2] Fix another VM_BUG_ON_PAGE(PageTail(page)) on mbind(2)

[Kirill A. Shutemov]

Dmitry Vyukov reported yet another VM_BUG_ON_PAGE(PageTail(page)) bug from
isolate_lru_page().

The fisrt patch fixes the bug by filter out non migratable VMAs in
queue_pages_test_walk(). There's no point to queue pages from non-migratable
VMA even for MPOL_MF_STRICT.

The second patch replace VM_BUG_ON_PAGE() with WARN_RATELIMIT() in
isolate_lru_page(). Most attempts to isolate tail pages are not fatal, as
these pages usually are not on LRU and will not be isolated.

v2:
 - address feedback from Michal Hocko;

Kirill A. Shutemov (2):
  mempolicy: do not try to queue pages from !vma_migratable()
  mm: downgrade VM_BUG in isolate_lru_page() to warning

 mm/mempolicy.c | 14 +++++---------
 mm/vmscan.c    |  2 +-
 2 files changed, 6 insertions(+), 10 deletions(-)

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2.7.0