mm/numa: Remove BUG_ON() in __handle_mm_fault()
authorRik van Riel <riel@redhat.com>
Tue, 29 Apr 2014 19:36:15 +0000 (15:36 -0400)
committerIngo Molnar <mingo@kernel.org>
Wed, 7 May 2014 11:33:48 +0000 (13:33 +0200)
commit107437febd495a50e2cd09c81bbaa84d30e57b07
tree8a80e9e879437dd2c601b55b46c3dc4fd29a7da9
parent68d1b02a58f5d9f584c1fb2923ed60ec68cbbd9b
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 <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>
mm/memory.c