[patch 02/17] mm/zsmalloc.c: fix the migrated zspage statistics.

[patch 02/17] mm/zsmalloc.c: fix the migrated zspage statistics.

[akpm]

From: Chanho Min <chanho.min@lge.com>
Subject: 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: 91537fee0013 ("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>
---

 mm/zsmalloc.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/mm/zsmalloc.c~mm-zsmallocc-fix-the-migrated-zspage-statistics
+++ a/mm/zsmalloc.c
@@ -2069,6 +2069,11 @@ static int zs_page_migrate(struct addres
 		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;
_