lkml.org 
[lkml]   [2014]   [Jul]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.14 92/94] mm/numa: Remove BUG_ON() in __handle_mm_fault()
    Date
    3.14-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Rik van Riel <riel@redhat.com>

    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>

    ---
    mm/memory.c | 3 ---
    1 file changed, 3 deletions(-)

    --- a/mm/memory.c
    +++ b/mm/memory.c
    @@ -3756,9 +3756,6 @@ static int __handle_mm_fault(struct mm_s
    }
    }

    - /* 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



    \
     
     \ /
      Last update: 2014-07-08 03:22    [W:2.795 / U:1.232 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site