From ec9f02384f6053f2a5417e82b65078edc5364a8d Mon Sep 17 00:00:00 2001
From: Roman Gushchin <guro@fb.com>
Date: Tue, 13 Aug 2019 15:37:41 -0700
Subject: mm: workingset: fix vmstat counters for shadow nodes
Memcg counters for shadow nodes are broken because the memcg pointer is
obtained in a wrong way. The following approach is used:
virt_to_page(xa_node)->mem_cgroup
Since commit 4d96ba353075 ("mm: memcg/slab: stop setting
page->mem_cgroup pointer for slab pages") page->mem_cgroup pointer isn't
set for slab pages, so memcg_from_slab_page() should be used instead.
Also I doubt that it ever worked correctly: virt_to_head_page() should
be used instead of virt_to_page(). Otherwise objects residing on tail
pages are not accounted, because only the head page contains a valid
mem_cgroup pointer. That was a case since the introduction of these
counters by the commit 68d48e6a2df5 ("mm: workingset: add vmstat counter
for shadow nodes").
Link: http://lkml.kernel.org/r/20190801233532.138743-1-guro@fb.com
Fixes: 4d96ba353075 ("mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/memcontrol.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
(limited to 'include/linux/memcontrol.h')
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 44c41462be33..2cd4359cb38c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -668,6 +668,7 @@ static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
int val);
+void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val);
static inline void mod_lruvec_state(struct lruvec *lruvec,
enum node_stat_item idx, int val)
@@ -1072,6 +1073,14 @@ static inline void mod_lruvec_page_state(struct page *page,
mod_node_page_state(page_pgdat(page), idx, val);
}
+static inline void __mod_lruvec_slab_state(void *p, enum node_stat_item idx,
+ int val)
+{
+ struct page *page = virt_to_head_page(p);
+
+ __mod_node_page_state(page_pgdat(page), idx, val);
+}
+
static inline
unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
gfp_t gfp_mask,
@@ -1159,6 +1168,16 @@ static inline void __dec_lruvec_page_state(struct page *page,
__mod_lruvec_page_state(page, idx, -1);
}
+static inline void __inc_lruvec_slab_state(void *p, enum node_stat_item idx)
+{
+ __mod_lruvec_slab_state(p, idx, 1);
+}
+
+static inline void __dec_lruvec_slab_state(void *p, enum node_stat_item idx)
+{
+ __mod_lruvec_slab_state(p, idx, -1);
+}
+
/* idx can be of type enum memcg_stat_item or node_stat_item */
static inline void inc_memcg_state(struct mem_cgroup *memcg,
int idx)
--
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