BACKPORT: cgroup: misc changes

Misc trivial changes to prepare for future changes.  No functional
difference.

* Expose cgroup_get(), cgroup_tryget() and cgroup_parent().

* Implement task_dfl_cgroup() which dereferences css_set->dfl_cgrp.

* Rename cgroup_stats_show() to cgroup_stat_show() for consistency
  with the file name.

Signed-off-by: Tejun Heo <tj@kernel.org>

(cherry picked from commit 3e48930cc74f0c212ee1838f89ad0ca7fcf2fea1)

Conflicts:
        kernel/cgroup/cgroup.c

(1. manual merge because kernel/cgroup/cgroup.c is under kernel/cgroup.c
2. cgroup_stats_show change is skipped because the function dos not exist)

Bug: 111308141
Test: modified lmkd to use PSI and tested using lmkd_unit_test

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I756ee3dcf0d0f3da69cd1b58e644271625053538
This commit is contained in:
Tejun Heo 2017-08-11 05:49:01 -07:00 committed by Suren Baghdasaryan
parent 4c29ebef46
commit 86c5c11aa0
2 changed files with 24 additions and 20 deletions

View file

@ -388,6 +388,16 @@ static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
percpu_ref_put_many(&css->refcnt, n);
}
static inline void cgroup_get(struct cgroup *cgrp)
{
css_get(&cgrp->self);
}
static inline bool cgroup_tryget(struct cgroup *cgrp)
{
return css_tryget(&cgrp->self);
}
static inline void cgroup_put(struct cgroup *cgrp)
{
css_put(&cgrp->self);
@ -500,6 +510,20 @@ static inline struct cgroup *task_cgroup(struct task_struct *task,
return task_css(task, subsys_id)->cgroup;
}
static inline struct cgroup *task_dfl_cgroup(struct task_struct *task)
{
return task_css_set(task)->dfl_cgrp;
}
static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
{
struct cgroup_subsys_state *parent_css = cgrp->self.parent;
if (parent_css)
return container_of(parent_css, struct cgroup, self);
return NULL;
}
/**
* cgroup_is_descendant - test ancestry
* @cgrp: the cgroup to be tested

View file

@ -361,15 +361,6 @@ static void cgroup_idr_remove(struct idr *idr, int id)
spin_unlock_bh(&cgroup_idr_lock);
}
static struct cgroup *cgroup_parent(struct cgroup *cgrp)
{
struct cgroup_subsys_state *parent_css = cgrp->self.parent;
if (parent_css)
return container_of(parent_css, struct cgroup, self);
return NULL;
}
/* subsystems visibly enabled on a cgroup */
static u16 cgroup_control(struct cgroup *cgrp)
{
@ -487,17 +478,6 @@ static inline bool cgroup_is_dead(const struct cgroup *cgrp)
return !(cgrp->self.flags & CSS_ONLINE);
}
static void cgroup_get(struct cgroup *cgrp)
{
WARN_ON_ONCE(cgroup_is_dead(cgrp));
css_get(&cgrp->self);
}
static bool cgroup_tryget(struct cgroup *cgrp)
{
return css_tryget(&cgrp->self);
}
struct cgroup_subsys_state *of_css(struct kernfs_open_file *of)
{
struct cgroup *cgrp = of->kn->parent->priv;