[patch 4/4] mm: memcontrol: add memory.vmstat to default hierarchy

Johannes Weiner
2014-08-04T21:14:57Z

Provide basic per-memcg vmstat-style statistics on LRU sizes,
allocated and freed pages, major and minor faults.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
Documentation/cgroups/unified-hierarchy.txt | 8 ++++++
mm/memcontrol.c | 40 +++++++++++++++++++++++++++++
2 files changed, 48 insertions(+)

diff --git a/Documentation/cgroups/unified-hierarchy.txt b/Documentation/cgroups/unified-hierarchy.txt
index 6c52c926810f..180b260c510a 100644
--- a/Documentation/cgroups/unified-hierarchy.txt
+++ b/Documentation/cgroups/unified-hierarchy.txt
@@ -337,6 +337,14 @@ supported and the interface files "release_agent" and
- memory.max provides a hard upper limit as a last-resort backup to
memory.high for situations with aggressive isolation requirements.

+- memory.stat has been replaced by memory.vmstat, which provides
+ page-based statistics in the style of /proc/vmstat.
+
+ As cgroups are now always hierarchical and no longer allow tasks in
+ intermediate levels, the local state is irrelevant and all
+ statistics represent the state of the entire hierarchy rooted at the
+ given group.
+

5. Planned Changes

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 461834c86b94..6502e1cfc0fc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6336,6 +6336,42 @@ static ssize_t memory_max_write(struct kernfs_open_file *of,
return nbytes;
}

+static u64 tree_events(struct mem_cgroup *memcg, int event)
+{
+ struct mem_cgroup *mi;
+ u64 val = 0;
+
+ for_each_mem_cgroup_tree(mi, memcg)
+ val += mem_cgroup_read_events(mi, event);
+ return val;
+}
+
+static int memory_vmstat_show(struct seq_file *m, void *v)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+ struct mem_cgroup *mi;
+ int i;
+
+ for (i = 0; i < NR_LRU_LISTS; i++) {
+ u64 val = 0;
+
+ for_each_mem_cgroup_tree(mi, memcg)
+ val += mem_cgroup_nr_lru_pages(mi, BIT(i));
+ seq_printf(m, "%s %llu\n", vmstat_text[NR_LRU_BASE + i], val);
+ }
+
+ seq_printf(m, "pgalloc %llu\n",
+ tree_events(memcg, MEM_CGROUP_EVENTS_PGPGIN));
+ seq_printf(m, "pgfree %llu\n",
+ tree_events(memcg, MEM_CGROUP_EVENTS_PGPGOUT));
+ seq_printf(m, "pgfault %llu\n",
+ tree_events(memcg, MEM_CGROUP_EVENTS_PGFAULT));
+ seq_printf(m, "pgmajfault %llu\n",
+ tree_events(memcg, MEM_CGROUP_EVENTS_PGMAJFAULT));
+
+ return 0;
+}
+
static struct cftype memory_files[] = {
{
.name = "current",
@@ -6351,6 +6387,10 @@ static struct cftype memory_files[] = {
.read_u64 = memory_max_read,
.write = memory_max_write,
},
+ {
+ .name = "vmstat",
+ .seq_show = memory_vmstat_show,
+ },
};

struct cgroup_subsys memory_cgrp_subsys = {
--
2.0.3