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authorRoman Gushchin <guro@fb.com>2019-08-13 15:37:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-08-13 16:06:52 -0700
commitec9f02384f6053f2a5417e82b65078edc5364a8d (patch)
tree18f6d560869e620c21dacd71353f235c6a13f00a /mm
parent951531691c4bcaa59f56a316e018bc2ff1ddf855 (diff)
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>
Diffstat (limited to 'mm')
-rw-r--r--mm/memcontrol.c20
-rw-r--r--mm/workingset.c10
2 files changed, 24 insertions, 6 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2e405e058eda..6f5c0c517c49 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -768,6 +768,26 @@ void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
__this_cpu_write(pn->lruvec_stat_cpu->count[idx], x);
}
+void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val)
+{
+ struct page *page = virt_to_head_page(p);
+ pg_data_t *pgdat = page_pgdat(page);
+ struct mem_cgroup *memcg;
+ struct lruvec *lruvec;
+
+ rcu_read_lock();
+ memcg = memcg_from_slab_page(page);
+
+ /* Untracked pages have no memcg, no lruvec. Update only the node */
+ if (!memcg || memcg == root_mem_cgroup) {
+ __mod_node_page_state(pgdat, idx, val);
+ } else {
+ lruvec = mem_cgroup_lruvec(pgdat, memcg);
+ __mod_lruvec_state(lruvec, idx, val);
+ }
+ rcu_read_unlock();
+}
+
/**
* __count_memcg_events - account VM events in a cgroup
* @memcg: the memory cgroup
diff --git a/mm/workingset.c b/mm/workingset.c
index e0b4edcb88c8..c963831d354f 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -380,14 +380,12 @@ void workingset_update_node(struct xa_node *node)
if (node->count && node->count == node->nr_values) {
if (list_empty(&node->private_list)) {
list_lru_add(&shadow_nodes, &node->private_list);
- __inc_lruvec_page_state(virt_to_page(node),
- WORKINGSET_NODES);
+ __inc_lruvec_slab_state(node, WORKINGSET_NODES);
}
} else {
if (!list_empty(&node->private_list)) {
list_lru_del(&shadow_nodes, &node->private_list);
- __dec_lruvec_page_state(virt_to_page(node),
- WORKINGSET_NODES);
+ __dec_lruvec_slab_state(node, WORKINGSET_NODES);
}
}
}
@@ -480,7 +478,7 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
}
list_lru_isolate(lru, item);
- __dec_lruvec_page_state(virt_to_page(node), WORKINGSET_NODES);
+ __dec_lruvec_slab_state(node, WORKINGSET_NODES);
spin_unlock(lru_lock);
@@ -503,7 +501,7 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
* shadow entries we were tracking ...
*/
xas_store(&xas, NULL);
- __inc_lruvec_page_state(virt_to_page(node), WORKINGSET_NODERECLAIM);
+ __inc_lruvec_slab_state(node, WORKINGSET_NODERECLAIM);
out_invalid:
xa_unlock_irq(&mapping->i_pages);