mm: memcontrol: give the kmem states more descriptive names
On any given memcg, the kmem accounting feature has three separate
states: not initialized, structures allocated, and actively accounting
slab memory. These are represented through a combination of the
kmem_acct_activated and kmem_acct_active flags, which is confusing.
Convert to a kmem_state enum with the states NONE, ALLOCATED, and
ONLINE. Then rename the functions to modify the state accordingly.
This follows the nomenclature of css object states more closely.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.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 71dced1..24b6bde 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2378,7 +2378,7 @@
struct page_counter *counter;
int ret;
- if (!memcg_kmem_is_active(memcg))
+ if (!memcg_kmem_online(memcg))
return 0;
if (!page_counter_try_charge(&memcg->kmem, nr_pages, &counter))
@@ -2861,14 +2861,13 @@
}
#ifdef CONFIG_MEMCG_KMEM
-static int memcg_activate_kmem(struct mem_cgroup *memcg)
+static int memcg_online_kmem(struct mem_cgroup *memcg)
{
int err = 0;
int memcg_id;
BUG_ON(memcg->kmemcg_id >= 0);
- BUG_ON(memcg->kmem_acct_activated);
- BUG_ON(memcg->kmem_acct_active);
+ BUG_ON(memcg->kmem_state);
/*
* For simplicity, we won't allow this to be disabled. It also can't
@@ -2898,14 +2897,13 @@
static_branch_inc(&memcg_kmem_enabled_key);
/*
- * A memory cgroup is considered kmem-active as soon as it gets
+ * A memory cgroup is considered kmem-online as soon as it gets
* kmemcg_id. Setting the id after enabling static branching will
* guarantee no one starts accounting before all call sites are
* patched.
*/
memcg->kmemcg_id = memcg_id;
- memcg->kmem_acct_activated = true;
- memcg->kmem_acct_active = true;
+ memcg->kmem_state = KMEM_ONLINE;
out:
return err;
}
@@ -2917,8 +2915,8 @@
mutex_lock(&memcg_limit_mutex);
/* Top-level cgroup doesn't propagate from root */
- if (!memcg_kmem_is_active(memcg)) {
- ret = memcg_activate_kmem(memcg);
+ if (!memcg_kmem_online(memcg)) {
+ ret = memcg_online_kmem(memcg);
if (ret)
goto out;
}
@@ -2938,11 +2936,12 @@
mutex_lock(&memcg_limit_mutex);
/*
- * If the parent cgroup is not kmem-active now, it cannot be activated
- * after this point, because it has at least one child already.
+ * If the parent cgroup is not kmem-online now, it cannot be
+ * onlined after this point, because it has at least one child
+ * already.
*/
- if (memcg_kmem_is_active(parent))
- ret = memcg_activate_kmem(memcg);
+ if (memcg_kmem_online(parent))
+ ret = memcg_online_kmem(memcg);
mutex_unlock(&memcg_limit_mutex);
return ret;
}
@@ -3590,22 +3589,21 @@
return tcp_init_cgroup(memcg);
}
-static void memcg_deactivate_kmem(struct mem_cgroup *memcg)
+static void memcg_offline_kmem(struct mem_cgroup *memcg)
{
struct cgroup_subsys_state *css;
struct mem_cgroup *parent, *child;
int kmemcg_id;
- if (!memcg->kmem_acct_active)
+ if (memcg->kmem_state != KMEM_ONLINE)
return;
-
/*
- * Clear the 'active' flag before clearing memcg_caches arrays entries.
- * Since we take the slab_mutex in memcg_deactivate_kmem_caches(), it
- * guarantees no cache will be created for this cgroup after we are
- * done (see memcg_create_kmem_cache()).
+ * Clear the online state before clearing memcg_caches array
+ * entries. The slab_mutex in memcg_deactivate_kmem_caches()
+ * guarantees that no cache will be created for this cgroup
+ * after we are done (see memcg_create_kmem_cache()).
*/
- memcg->kmem_acct_active = false;
+ memcg->kmem_state = KMEM_ALLOCATED;
memcg_deactivate_kmem_caches(memcg);
@@ -3636,9 +3634,9 @@
memcg_free_cache_id(kmemcg_id);
}
-static void memcg_destroy_kmem(struct mem_cgroup *memcg)
+static void memcg_free_kmem(struct mem_cgroup *memcg)
{
- if (memcg->kmem_acct_activated) {
+ if (memcg->kmem_state == KMEM_ALLOCATED) {
memcg_destroy_kmem_caches(memcg);
static_branch_dec(&memcg_kmem_enabled_key);
WARN_ON(page_counter_read(&memcg->kmem));
@@ -3651,11 +3649,11 @@
return 0;
}
-static void memcg_deactivate_kmem(struct mem_cgroup *memcg)
+static void memcg_offline_kmem(struct mem_cgroup *memcg)
{
}
-static void memcg_destroy_kmem(struct mem_cgroup *memcg)
+static void memcg_free_kmem(struct mem_cgroup *memcg)
{
}
#endif
@@ -4308,7 +4306,7 @@
vmpressure_cleanup(&memcg->vmpressure);
- memcg_deactivate_kmem(memcg);
+ memcg_offline_kmem(memcg);
wb_memcg_offline(memcg);
}
@@ -4324,7 +4322,7 @@
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- memcg_destroy_kmem(memcg);
+ memcg_free_kmem(memcg);
#ifdef CONFIG_INET
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
static_branch_dec(&memcg_sockets_enabled_key);