Commit c0a602ad authored by Rabin Vincent's avatar Rabin Vincent Committed by Greg Kroah-Hartman

mm: prevent NR_ISOLATE_* stats from going negative

commit fc280fe8 upstream.

Commit 6afcf8ef ("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: 6afcf8ef ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration")
Link: http://lkml.kernel.org/r/1492683865-27549-1-git-send-email-rabin.vincent@axis.comSigned-off-by: default avatarRabin Vincent <rabinv@axis.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Ming Ling <ming.ling@spreadtrum.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d80e9071
......@@ -183,9 +183,9 @@ void putback_movable_pages(struct list_head *l)
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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