From 107437febd495a50e2cd09c81bbaa84d30e57b07 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Tue, 29 Apr 2014 15:36:15 -0400 Subject: [PATCH] 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: Rik van Riel Reviewed-by: Naoya Horiguchi Reported-by: Sunil Pandey Signed-off-by: Peter Zijlstra Cc: Andrew Morton Cc: Johannes Weiner Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: Mel Gorman Cc: linux-mm@kvack.org Cc: lwoodman@redhat.com Cc: dave.hansen@intel.com Link: http://lkml.kernel.org/r/20140429153615.2d72098e@annuminas.surriel.com Signed-off-by: Ingo Molnar --- mm/memory.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index d0f0bef3be48..9c2dc659f6f6 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -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 * run pte_offset_map on the pmd, if an huge pmd could -- 2.20.1