From: Shakeel Butt <shakeel.butt@linux.dev>
To: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Muchun Song <muchun.song@linux.dev>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 5/7] memcg: pr_warn_once for unexpected events and stats
Date: Fri, 26 Apr 2024 17:37:31 -0700 [thread overview]
Message-ID: <20240427003733.3898961-6-shakeel.butt@linux.dev> (raw)
In-Reply-To: <20240427003733.3898961-1-shakeel.butt@linux.dev>
To reduce memory usage by the memcg events and stats, the kernel uses
indirection table and only allocate stats and events which are being
used by the memcg code. To make this more robust, let's add warnings
where unexpected stats and events indexes are used.
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
---
mm/memcontrol.c | 43 ++++++++++++++++++++++++++++++++++---------
1 file changed, 34 insertions(+), 9 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 103e0e53e20a..36145089dcf5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -671,9 +671,11 @@ unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx)
return node_page_state(lruvec_pgdat(lruvec), idx);
i = memcg_stats_index(idx);
- if (i >= 0) {
+ if (likely(i >= 0)) {
pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
x = READ_ONCE(pn->lruvec_stats->state[i]);
+ } else {
+ pr_warn_once("%s: stat item index: %d\n", __func__, idx);
}
#ifdef CONFIG_SMP
if (x < 0)
@@ -693,9 +695,11 @@ unsigned long lruvec_page_state_local(struct lruvec *lruvec,
return node_page_state(lruvec_pgdat(lruvec), idx);
i = memcg_stats_index(idx);
- if (i >= 0) {
+ if (likely(i >= 0)) {
pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
x = READ_ONCE(pn->lruvec_stats->state_local[i]);
+ } else {
+ pr_warn_once("%s: stat item index: %d\n", __func__, idx);
}
#ifdef CONFIG_SMP
if (x < 0)
@@ -922,8 +926,10 @@ unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
long x;
int i = memcg_stats_index(idx);
- if (i < 0)
+ if (unlikely(i < 0)) {
+ pr_warn_once("%s: stat item index: %d\n", __func__, idx);
return 0;
+ }
x = READ_ONCE(memcg->vmstats->state[i]);
#ifdef CONFIG_SMP
@@ -959,8 +965,13 @@ void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val)
{
int i = memcg_stats_index(idx);
- if (mem_cgroup_disabled() || i < 0)
+ if (mem_cgroup_disabled())
+ return;
+
+ if (unlikely(i < 0)) {
+ pr_warn_once("%s: stat item index: %d\n", __func__, idx);
return;
+ }
__this_cpu_add(memcg->vmstats_percpu->state[i], val);
memcg_rstat_updated(memcg, memcg_state_val_in_pages(idx, val));
@@ -972,8 +983,10 @@ static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
long x;
int i = memcg_stats_index(idx);
- if (i < 0)
+ if (unlikely(i < 0)) {
+ pr_warn_once("%s: stat item index: %d\n", __func__, idx);
return 0;
+ }
x = READ_ONCE(memcg->vmstats->state_local[i]);
#ifdef CONFIG_SMP
@@ -991,8 +1004,10 @@ static void __mod_memcg_lruvec_state(struct lruvec *lruvec,
struct mem_cgroup *memcg;
int i = memcg_stats_index(idx);
- if (i < 0)
+ if (unlikely(i < 0)) {
+ pr_warn_once("%s: stat item index: %d\n", __func__, idx);
return;
+ }
pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
memcg = pn->memcg;
@@ -1107,8 +1122,13 @@ void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
{
int index = memcg_events_index(idx);
- if (mem_cgroup_disabled() || index < 0)
+ if (mem_cgroup_disabled())
+ return;
+
+ if (unlikely(index < 0)) {
+ pr_warn_once("%s: event item index: %d\n", __func__, idx);
return;
+ }
memcg_stats_lock();
__this_cpu_add(memcg->vmstats_percpu->events[index], count);
@@ -1120,8 +1140,11 @@ static unsigned long memcg_events(struct mem_cgroup *memcg, int event)
{
int index = memcg_events_index(event);
- if (index < 0)
+ if (unlikely(index < 0)) {
+ pr_warn_once("%s: event item index: %d\n", __func__, event);
return 0;
+ }
+
return READ_ONCE(memcg->vmstats->events[index]);
}
@@ -1129,8 +1152,10 @@ static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
{
int index = memcg_events_index(event);
- if (index < 0)
+ if (unlikely(index < 0)) {
+ pr_warn_once("%s: event item index: %d\n", __func__, event);
return 0;
+ }
return READ_ONCE(memcg->vmstats->events_local[index]);
}
--
2.43.0
next prev parent reply other threads:[~2024-04-27 0:37 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-27 0:37 [PATCH v2 0/7] memcg: reduce memory consumption by memcg stats Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 1/7] memcg: reduce memory size of mem_cgroup_events_index Shakeel Butt
2024-04-27 0:42 ` Yosry Ahmed
2024-04-27 1:15 ` Shakeel Butt
2024-04-29 15:36 ` Roman Gushchin
2024-04-27 0:37 ` [PATCH v2 2/7] memcg: dynamically allocate lruvec_stats Shakeel Butt
2024-04-27 1:23 ` Yosry Ahmed
2024-04-29 15:50 ` Roman Gushchin
2024-04-29 19:46 ` Shakeel Butt
2024-04-29 21:02 ` Roman Gushchin
2024-04-29 21:59 ` Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 3/7] memcg: reduce memory for the lruvec and memcg stats Shakeel Butt
2024-04-27 0:51 ` Yosry Ahmed
2024-04-27 1:16 ` Shakeel Butt
2024-04-27 1:18 ` Yosry Ahmed
2024-04-29 16:00 ` Roman Gushchin
2024-04-29 20:00 ` Shakeel Butt
2024-04-29 17:35 ` T.J. Mercier
2024-04-29 20:13 ` Shakeel Butt
2024-04-29 22:23 ` T.J. Mercier
2024-04-27 0:37 ` [PATCH v2 4/7] memcg: cleanup __mod_memcg_lruvec_state Shakeel Butt
2024-04-27 0:53 ` Yosry Ahmed
2024-04-29 15:45 ` Roman Gushchin
2024-04-27 0:37 ` Shakeel Butt [this message]
2024-04-27 0:58 ` [PATCH v2 5/7] memcg: pr_warn_once for unexpected events and stats Yosry Ahmed
2024-04-27 1:18 ` Shakeel Butt
2024-04-27 14:22 ` Johannes Weiner
2024-04-29 19:54 ` Shakeel Butt
2024-04-29 16:06 ` Roman Gushchin
2024-04-29 19:56 ` Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 6/7] memcg: use proper type for mod_memcg_state Shakeel Butt
2024-04-27 0:37 ` [PATCH v2 7/7] mm: cleanup WORKINGSET_NODES in workingset Shakeel Butt
2024-04-29 16:07 ` Roman Gushchin
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