From f6498b776d280b30a4614d8261840961e993c2c8 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Thu, 19 May 2022 14:08:53 -0700
Subject: mm: zswap: add basic meminfo and vmstat coverage

Currently it requires poking at debugfs to figure out the size and
population of the zswap cache on a host.  There are no counters for reads
and writes against the cache.  As a result, it's difficult to understand
zswap behavior on production systems.

Print zswap memory consumption and how many pages are zswapped out in
/proc/meminfo.  Count zswapouts and zswapins in /proc/vmstat.

Link: https://lkml.kernel.org/r/20220510152847.230957-6-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/vmstat.c | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'mm/vmstat.c')

diff --git a/mm/vmstat.c b/mm/vmstat.c
index b94a2e4723ff..da525bfb6f4a 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1396,6 +1396,10 @@ const char * const vmstat_text[] = {
 #ifdef CONFIG_KSM
 	"cow_ksm",
 #endif
+#ifdef CONFIG_ZSWAP
+	"zswpin",
+	"zswpout",
+#endif
 #ifdef CONFIG_X86
 	"direct_map_level2_splits",
 	"direct_map_level3_splits",
-- 
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