Commit 107437fe authored by Rik van Riel's avatar Rik van Riel Committed by Ingo Molnar

mm/numa: Remove BUG_ON() in __handle_mm_fault()

Changing PTEs and PMDs to pte_numa & pmd_numa is done with the
mmap_sem held for reading, which means a pmd can be instantiated
and turned into a numa one while __handle_mm_fault() is examining
the value of old_pmd.

If that happens, __handle_mm_fault() should just return and let
the page fault retry, instead of throwing an oops. This is
handled by the test for pmd_trans_huge(*pmd) below.
Signed-off-by: default avatarRik van Riel <riel@redhat.com>
Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: default avatarSunil Pandey <sunil.k.pandey@intel.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: linux-mm@kvack.org
Cc: lwoodman@redhat.com
Cc: dave.hansen@intel.com
Link: http://lkml.kernel.org/r/20140429153615.2d72098e@annuminas.surriel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 68d1b02a
...@@ -3900,9 +3900,6 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, ...@@ -3900,9 +3900,6 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
} }
} }
/* THP should already have been handled */
BUG_ON(pmd_numa(*pmd));
/* /*
* Use __pte_alloc instead of pte_alloc_map, because we can't * Use __pte_alloc instead of pte_alloc_map, because we can't
* run pte_offset_map on the pmd, if an huge pmd could * run pte_offset_map on the pmd, if an huge pmd could
......
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