mm/zsmalloc.c: fix the migrated zspage statistics.

When zspage is migrated to the other zone, the zone page state should be
updated as well, otherwise the NR_ZSPAGE for each zone shows wrong
counts including proc/zoneinfo in practice.

Link: http://lkml.kernel.org/r/1575434841-48009-1-git-send-email-chanho.min@lge.com
Fixes: 06d42b31dbfd ("mm: add NR_ZSMALLOC to vmstat")
Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Jinsuk Choi <jjinsuk.choi@lge.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>        [4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 2b2b9aae8a3c63dfc3c8a1b0551ec8c415d69567..22d17ecfe7df464412426e2dc4079c541f28ae4d 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -2069,6 +2069,11 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage,
                zs_pool_dec_isolated(pool);
        }
 
+       if (page_zone(newpage) != page_zone(page)) {
+               dec_zone_page_state(page, NR_ZSPAGES);
+               inc_zone_page_state(newpage, NR_ZSPAGES);
+       }
+
        reset_page(page);
        put_page(page);
        page = newpage;