diff mbox series

[RFC,2/2] memcg: Adapt cgroup.top into per-memcg

Message ID 20220826011503.103894-3-lujialin4@huawei.com (mailing list archive)
State New
Headers show
Series Introduce cgroup.top interface | expand

Commit Message

Lu Jialin Aug. 26, 2022, 1:15 a.m. UTC
cgroup.top is able to show resource usage information for each cgroups.
Currently only memory usage is monitored ,including usage,anon,file,
kmem(Bytes), stats for other resource types would be added as well.

Show case:
/ # mount -t cgroup2 none /sys/fs/cgroup
/ # cd /sys/fs/cgroup/
/sys/fs/cgroup # echo "+memory" > cgroup.subtree_control
/sys/fs/cgroup # mkdir test1
/sys/fs/cgroup # mkdir test2
/sys/fs/cgroup # mkdir test3
/sys/fs/cgroup # echo $$ > test2/cgroup.procs
/sys/fs/cgroup # cd /test
/test # ./memcg_malloc 512000 &
/test # ./memcg_malloc 512000 &
/test # ./memcg_malloc 512000 &
/test # cd /sys/fs/cgroup
/sys/fs/cgroup # echo $$ > test1/cgroup.procs
/sys/fs/cgroup # cd /test
/test # ./memcg_malloc 512000 &
/test # cd /sys/fs/cgroup
/sys/fs/cgroup # echo $$ > test3/cgroup.procs
/sys/fs/cgroup # cat cgroup.top
memory top:
name            usage           anon            file            kernel
test2           1974272         1671168         0               270336
test1           700416          569344          0               94208
test3           196608          86016           0               86016

Signed-off-by: Lu Jialin <lujialin4@huawei.com>
Co-developed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
---
 mm/memcontrol.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)

Comments

Michal Hocko Aug. 26, 2022, 7:38 a.m. UTC | #1
On Fri 26-08-22 09:15:03, Lu Jialin wrote:
> cgroup.top is able to show resource usage information for each cgroups.
> Currently only memory usage is monitored ,including usage,anon,file,
> kmem(Bytes), stats for other resource types would be added as well.
> 
> Show case:
> / # mount -t cgroup2 none /sys/fs/cgroup
> / # cd /sys/fs/cgroup/
> /sys/fs/cgroup # echo "+memory" > cgroup.subtree_control
> /sys/fs/cgroup # mkdir test1
> /sys/fs/cgroup # mkdir test2
> /sys/fs/cgroup # mkdir test3
> /sys/fs/cgroup # echo $$ > test2/cgroup.procs
> /sys/fs/cgroup # cd /test
> /test # ./memcg_malloc 512000 &
> /test # ./memcg_malloc 512000 &
> /test # ./memcg_malloc 512000 &
> /test # cd /sys/fs/cgroup
> /sys/fs/cgroup # echo $$ > test1/cgroup.procs
> /sys/fs/cgroup # cd /test
> /test # ./memcg_malloc 512000 &
> /test # cd /sys/fs/cgroup
> /sys/fs/cgroup # echo $$ > test3/cgroup.procs
> /sys/fs/cgroup # cat cgroup.top
> memory top:
> name            usage           anon            file            kernel
> test2           1974272         1671168         0               270336
> test1           700416          569344          0               94208
> test3           196608          86016           0               86016

This information is already present in memory.stat and can be easily
post-processed to generate similar output. Why is that insufficient?
diff mbox series

Patch

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b69979c9ced5..e4d4afefe5a6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5480,6 +5480,92 @@  static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu)
 	}
 }
 
+static int cmp_usage(const void *a, const void *b)
+{
+	struct mem_cgroup *memcg_a = *(struct mem_cgroup **)a;
+	struct mem_cgroup *memcg_b = *(struct mem_cgroup **)b;
+
+	return page_counter_read(&memcg_b->memory) -
+	       page_counter_read(&memcg_a->memory);
+}
+
+static int child_memcg_css_count(struct cgroup_subsys_state *css)
+{
+	struct cgroup_subsys_state *child;
+	int count = 0;
+
+	css_for_each_child(child, css)
+		count++;
+
+	return count;
+}
+
+struct memory_top_info {
+	const char *name;
+	unsigned long idx;
+};
+
+static const struct memory_top_info memory_info[] = {
+	{"anon",			NR_ANON_MAPPED},
+	{"file",			NR_FILE_PAGES},
+	{"kernel",			MEMCG_KMEM},
+};
+
+static void mem_cgroup_css_top(struct cgroup_subsys_state *css,
+			       struct seq_file *seq)
+{
+	struct mem_cgroup **array;
+	struct cgroup_subsys_state *child;
+	int memcg_number = child_memcg_css_count(css);
+	int i, j;
+	int count = 0;
+
+	mem_cgroup_flush_stats();
+
+	array = kvmalloc_array(memcg_number, sizeof(struct mem_cgroup *),
+			       GFP_KERNEL);
+	if (!array)
+		return;
+
+	css_for_each_child(child, css) {
+		struct mem_cgroup *memcg = mem_cgroup_from_css(child);
+
+		if (count == memcg_number)
+			break;
+		array[count++] = memcg;
+	}
+
+	sort(array, memcg_number, sizeof(struct mem_cgroup *), cmp_usage, NULL);
+
+	seq_printf(seq, "%s top:\n", css->ss->name);
+
+	seq_puts(seq, "name\t\tusage\t\t");
+	for (j = 0; j < ARRAY_SIZE(memory_info); j++)
+		seq_printf(seq, "%s\t\t", memory_info[j].name);
+	seq_puts(seq, "\n");
+
+	for (i = 0; i < memcg_number; i++) {
+		struct mem_cgroup *memcg = array[i];
+		unsigned long usage = page_counter_read(&memcg->memory);
+		struct cgroup *cgroup = memcg->css.cgroup;
+		const char *name = cgroup->kn->name;
+
+		seq_printf(seq, "%s\t\t%lu\t\t", name, usage * PAGE_SIZE);
+		for (j = 0; j < ARRAY_SIZE(memory_info); j++) {
+			u64 size;
+
+			size = memcg_page_state_output(memcg,
+						       memory_info[j].idx);
+			seq_printf(seq, "%llu\t\t", size);
+		}
+		seq_puts(seq, "\n");
+	}
+
+	kvfree(array);
+
+}
+
+
 #ifdef CONFIG_MMU
 /* Handlers for move charge at task migration. */
 static int mem_cgroup_do_precharge(unsigned long count)
@@ -6600,6 +6686,7 @@  struct cgroup_subsys memory_cgrp_subsys = {
 	.css_free = mem_cgroup_css_free,
 	.css_reset = mem_cgroup_css_reset,
 	.css_rstat_flush = mem_cgroup_css_rstat_flush,
+	.css_top = mem_cgroup_css_top,
 	.can_attach = mem_cgroup_can_attach,
 	.cancel_attach = mem_cgroup_cancel_attach,
 	.post_attach = mem_cgroup_move_task,