memcg: show real limit under hierarchy mode
Show "real" limit of memcg. This helps my debugging and maybe useful for
users.
While testing hierarchy like this
mount -t cgroup none /cgroup -t memory
mkdir /cgroup/A
set use_hierarchy==1 to "A"
mkdir /cgroup/A/01
mkdir /cgroup/A/01/02
mkdir /cgroup/A/01/03
mkdir /cgroup/A/01/03/04
mkdir /cgroup/A/08
mkdir /cgroup/A/08/01
....
and set each own limit to them, "real" limit of each memcg is unclear.
This patch shows real limit by checking all ancestors.
Changelog: (v1) -> (v2)
- remove "if" and use "min(a,b)"
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c7d78ec..8d2e5c8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1782,6 +1782,34 @@
return ret;
}
+static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
+ unsigned long long *mem_limit, unsigned long long *memsw_limit)
+{
+ struct cgroup *cgroup;
+ unsigned long long min_limit, min_memsw_limit, tmp;
+
+ min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
+ min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+ cgroup = memcg->css.cgroup;
+ if (!memcg->use_hierarchy)
+ goto out;
+
+ while (cgroup->parent) {
+ cgroup = cgroup->parent;
+ memcg = mem_cgroup_from_cont(cgroup);
+ if (!memcg->use_hierarchy)
+ break;
+ tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
+ min_limit = min(min_limit, tmp);
+ tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+ min_memsw_limit = min(min_memsw_limit, tmp);
+ }
+out:
+ *mem_limit = min_limit;
+ *memsw_limit = min_memsw_limit;
+ return;
+}
+
static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
{
struct mem_cgroup *mem;
@@ -1855,6 +1883,13 @@
cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);
}
+ {
+ unsigned long long limit, memsw_limit;
+ memcg_get_hierarchical_limit(mem_cont, &limit, &memsw_limit);
+ cb->fill(cb, "hierarchical_memory_limit", limit);
+ if (do_swap_account)
+ cb->fill(cb, "hierarchical_memsw_limit", memsw_limit);
+ }
#ifdef CONFIG_DEBUG_VM
cb->fill(cb, "inactive_ratio", calc_inactive_ratio(mem_cont, NULL));