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| author | Rik van Riel <riel@redhat.com> | 2014-04-29 15:36:15 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-09 11:18:29 -0700 |
| commit | 347f31e9ad98b6bc15c50c72ae385b50bd7149b0 (patch) | |
| tree | 36a632d03a8cb757abf7779dd8871e9328a48387 /mm/memory.c | |
| parent | c10760de1dfd589d77fded52838e99df1a38a8c4 (diff) | |
| download | lwn-347f31e9ad98b6bc15c50c72ae385b50bd7149b0.tar.gz lwn-347f31e9ad98b6bc15c50c72ae385b50bd7149b0.zip | |
mm/numa: Remove BUG_ON() in __handle_mm_fault()
commit 107437febd495a50e2cd09c81bbaa84d30e57b07 upstream.
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 <riel@redhat.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Sunil Pandey <sunil.k.pandey@intel.com>
Signed-off-by: Peter 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.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/mm/memory.c b/mm/memory.c index 49e930f9ed46..2121d8b8db56 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3756,9 +3756,6 @@ 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 |