cgroup: remove css_parent()
cgroup in general is moving towards using cgroup_subsys_state as the
fundamental structural component and css_parent() was introduced to
convert from using cgroup->parent to css->parent. It was quite some
time ago and we're moving forward with making css more prominent.
This patch drops the trivial wrapper css_parent() and let the users
dereference css->parent. While at it, explicitly mark fields of css
which are public and immutable.
v2: New usage from device_cgroup.c converted.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b638a79..a5e0417 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1540,7 +1540,7 @@
int mem_cgroup_swappiness(struct mem_cgroup *memcg)
{
/* root ? */
- if (!css_parent(&memcg->css))
+ if (!memcg->css.parent)
return vm_swappiness;
return memcg->swappiness;
@@ -4909,7 +4909,7 @@
{
int retval = 0;
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css));
+ struct mem_cgroup *parent_memcg = mem_cgroup_from_css(memcg->css.parent);
mutex_lock(&memcg_create_mutex);
@@ -5207,8 +5207,8 @@
if (!memcg->use_hierarchy)
goto out;
- while (css_parent(&memcg->css)) {
- memcg = mem_cgroup_from_css(css_parent(&memcg->css));
+ while (memcg->css.parent) {
+ memcg = mem_cgroup_from_css(memcg->css.parent);
if (!memcg->use_hierarchy)
break;
tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
@@ -5443,7 +5443,7 @@
struct cftype *cft, u64 val)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
+ struct mem_cgroup *parent = mem_cgroup_from_css(memcg->css.parent);
if (val > 100 || !parent)
return -EINVAL;
@@ -5790,7 +5790,7 @@
struct cftype *cft, u64 val)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
+ struct mem_cgroup *parent = mem_cgroup_from_css(memcg->css.parent);
/* cannot set to root cgroup and only 0 and 1 are allowed */
if (!parent || !((val == 0) || (val == 1)))
@@ -6407,7 +6407,7 @@
mem_cgroup_css_online(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css));
+ struct mem_cgroup *parent = mem_cgroup_from_css(css->parent);
if (css->id > MEM_CGROUP_ID_MAX)
return -ENOSPC;