4.10-stable review patch.  If anyone has any objections, please let me know.

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

From: Rabin Vincent <[email protected]>

commit fc280fe871449ead4bdbd1665fa52c7c01c64765 upstream.

Commit 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn
based migration") moved the dec_node_page_state() call (along with the
page_is_file_cache() call) to after putback_lru_page().

But page_is_file_cache() can change after putback_lru_page() is called,
so it should be called before putback_lru_page(), as it was before that
patch, to prevent NR_ISOLATE_* stats from going negative.

Without this fix, non-CONFIG_SMP kernels end up hanging in the
while(too_many_isolated()) { congestion_wait() } loop in
shrink_active_list() due to the negative stats.

 Mem-Info:
  active_anon:32567 inactive_anon:121 isolated_anon:1
  active_file:6066 inactive_file:6639 isolated_file:4294967295
                                                    ^^^^^^^^^^
  unevictable:0 dirty:115 writeback:0 unstable:0
  slab_reclaimable:2086 slab_unreclaimable:3167
  mapped:3398 shmem:18366 pagetables:1145 bounce:0
  free:1798 free_pcp:13 free_cma:0

Fixes: 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn based 
migration")
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Rabin Vincent <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Ming Ling <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 mm/migrate.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -183,9 +183,9 @@ void putback_movable_pages(struct list_h
                        unlock_page(page);
                        put_page(page);
                } else {
-                       putback_lru_page(page);
                        dec_node_page_state(page, NR_ISOLATED_ANON +
                                        page_is_file_cache(page));
+                       putback_lru_page(page);
                }
        }
 }


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