[PATCH 4.9 21/91] mm/zsmalloc.c: fix the migrated zspage statistics.

From: Greg Kroah-Hartman
Date: Sat Jan 11 2020 - 04:59:36 EST


From: Chanho Min <chanho.min@xxxxxxx>

commit ac8f05da5174c560de122c499ce5dfb5d0dfbee5 upstream.

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@xxxxxxx
Fixes: 91537fee0013 ("mm: add NR_ZSMALLOC to vmstat")
Signed-off-by: Chanho Min <chanho.min@xxxxxxx>
Signed-off-by: Jinsuk Choi <jjinsuk.choi@xxxxxxx>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [4.9+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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

--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -2138,6 +2138,11 @@ int zs_page_migrate(struct address_space
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;