Commit c8713d0b2312 ("mm: memcontrol: dump memory.stat during cgroup
OOM") made sure we dump all the stats in memory.stat during a cgroup
OOM, but it also introduced a slight behavioral change. The code used to
print the non-hierarchical v1 cgroup stats for the entire cgroup
subtree, not it only prints the v2 cgroup stats for the cgroup under
OOM.
Although v2 stats are a superset of v1 stats, some of them have
different naming. We also lost the non-hierarchical stats for the cgroup
under OOM in v1.
Move the v2 specific formatting from memory_stat_format() to
memcg_stat_format(), add memcg1_stat_format() for v1, and make
memory_stat_format() select between them based on cgroup version.
Since memory_stat_show() now works for both v1 & v2, drop
memcg_stat_show().
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
---
mm/memcontrol.c | 60 ++++++++++++++++++++++++++++---------------------
1 file changed, 35 insertions(+), 25 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5922940f92c9..2b492f8d540c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1551,7 +1551,7 @@ static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg,
return memcg_page_state(memcg, item) * memcg_page_state_unit(item);
}
-static void memory_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
+static void memcg_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
{
int i;
@@ -1604,6 +1604,17 @@ static void memory_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
WARN_ON_ONCE(seq_buf_has_overflowed(s));
}
+static void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
+
+static void memory_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
+{
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ memcg_stat_format(memcg, s);
+ else
+ memcg1_stat_format(memcg, s);
+ WARN_ON_ONCE(seq_buf_has_overflowed(s));
+}
+
#define K(x) ((x) << (PAGE_SHIFT-10))
/**
* mem_cgroup_print_oom_context: Print OOM information relevant to
@@ -4078,9 +4089,8 @@ static const unsigned int memcg1_events[] = {
PGMAJFAULT,
};
-static int memcg_stat_show(struct seq_file *m, void *v)
+static void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
{
- struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
unsigned long memory, memsw;
struct mem_cgroup *mi;
unsigned int i;
@@ -4095,18 +4105,18 @@ static int memcg_stat_show(struct seq_file *m, void *v)
if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
continue;
nr = memcg_page_state_local(memcg, memcg1_stats[i]);
- seq_printf(m, "%s %lu\n", memcg1_stat_names[i],
+ seq_buf_printf(s, "%s %lu\n", memcg1_stat_names[i],
nr * memcg_page_state_unit(memcg1_stats[i]));
}
for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
- seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]),
- memcg_events_local(memcg, memcg1_events[i]));
+ seq_buf_printf(s, "%s %lu\n", vm_event_name(memcg1_events[i]),
+ memcg_events_local(memcg, memcg1_events[i]));
for (i = 0; i < NR_LRU_LISTS; i++)
- seq_printf(m, "%s %lu\n", lru_list_name(i),
- memcg_page_state_local(memcg, NR_LRU_BASE + i) *
- PAGE_SIZE);
+ seq_buf_printf(s, "%s %lu\n", lru_list_name(i),
+ memcg_page_state_local(memcg, NR_LRU_BASE + i) *
+ PAGE_SIZE);
/* Hierarchical information */
memory = memsw = PAGE_COUNTER_MAX;
@@ -4114,11 +4124,11 @@ static int memcg_stat_show(struct seq_file *m, void *v)
memory = min(memory, READ_ONCE(mi->memory.max));
memsw = min(memsw, READ_ONCE(mi->memsw.max));
}
- seq_printf(m, "hierarchical_memory_limit %llu\n",
- (u64)memory * PAGE_SIZE);
+ seq_buf_printf(s, "hierarchical_memory_limit %llu\n",
+ (u64)memory * PAGE_SIZE);
if (do_memsw_account())
- seq_printf(m, "hierarchical_memsw_limit %llu\n",
- (u64)memsw * PAGE_SIZE);
+ seq_buf_printf(s, "hierarchical_memsw_limit %llu\n",
+ (u64)memsw * PAGE_SIZE);
for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
unsigned long nr;
@@ -4126,19 +4136,19 @@ static int memcg_stat_show(struct seq_file *m, void *v)
if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
continue;
nr = memcg_page_state(memcg, memcg1_stats[i]);
- seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i],
+ seq_buf_printf(s, "total_%s %llu\n", memcg1_stat_names[i],
(u64)nr * memcg_page_state_unit(memcg1_stats[i]));
}
for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
- seq_printf(m, "total_%s %llu\n",
- vm_event_name(memcg1_events[i]),
- (u64)memcg_events(memcg, memcg1_events[i]));
+ seq_buf_printf(s, "total_%s %llu\n",
+ vm_event_name(memcg1_events[i]),
+ (u64)memcg_events(memcg, memcg1_events[i]));
for (i = 0; i < NR_LRU_LISTS; i++)
- seq_printf(m, "total_%s %llu\n", lru_list_name(i),
- (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
- PAGE_SIZE);
+ seq_buf_printf(s, "total_%s %llu\n", lru_list_name(i),
+ (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
+ PAGE_SIZE);
#ifdef CONFIG_DEBUG_VM
{
@@ -4153,12 +4163,10 @@ static int memcg_stat_show(struct seq_file *m, void *v)
anon_cost += mz->lruvec.anon_cost;
file_cost += mz->lruvec.file_cost;
}
- seq_printf(m, "anon_cost %lu\n", anon_cost);
- seq_printf(m, "file_cost %lu\n", file_cost);
+ seq_buf_printf(s, "anon_cost %lu\n", anon_cost);
+ seq_buf_printf(s, "file_cost %lu\n", file_cost);
}
#endif
-
- return 0;
}
static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
@@ -4998,6 +5006,8 @@ static int mem_cgroup_slab_show(struct seq_file *m, void *p)
}
#endif
+static int memory_stat_show(struct seq_file *m, void *v);
+
static struct cftype mem_cgroup_legacy_files[] = {
{
.name = "usage_in_bytes",
@@ -5030,7 +5040,7 @@ static struct cftype mem_cgroup_legacy_files[] = {
},
{
.name = "stat",
- .seq_show = memcg_stat_show,
+ .seq_show = memory_stat_show,
},
{
.name = "force_empty",
--
2.40.1.495.gc816e09b53d-goog
