mm, numa: skip PTE-mapped THP on numa fault

We're going to have THP mapped with PTEs. It will confuse numabalancing.
Let's skip them for now.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory.c b/mm/memory.c
index bd59bfa0032e2098130377a3bb46e280edce7529..d26603384a0d2ccb96aeded2cad978480d9ca76b 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3186,6 +3186,12 @@ static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
                return 0;
        }
 
+       /* TODO: handle PTE-mapped THP */
+       if (PageCompound(page)) {
+               pte_unmap_unlock(ptep, ptl);
+               return 0;
+       }
+
        /*
         * Avoid grouping on RO pages in general. RO pages shouldn't hurt as
         * much anyway since they can be in shared cache state. This misses