cgroup: change cgroup_from_id() to css_from_id()

PATCH Superseded Li Zefan 2 participants 4 messages Aug 16, 2013 – Aug 19, 2013 cgroup

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Li Zefan

author

2013-08-16 07:05 UTC #0 lore raw

PATCH 1/1 cgroup: change cgroup_from_id() to css_from_id()

Now we want cgroup core to always provide the css to use to the subsystems, so change this API to css_from_id().

Uninline css_from_id(), because it's getting bigger and cgroup_css() has been unexported.

While at it, remove the #ifdef.

Signed-off-by Li Zefan <[email protected]>

---
 include/linux/cgroup.h | 20 ++------------------
 kernel/cgroup.c        | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 18 deletions(-)

include/linux/cgroup.h +2 ~~-18~~

index 11a6419..50186f0 100644
@@ -742,27 +742,11 @@ static inline struct cgroup *task_cgroup(struct task_struct *task,
 	return task_css(task, subsys_id)->cgroup;
 }
 
-/**
- * cgroup_from_id - lookup cgroup by id
- * @ss: cgroup subsys to be looked into
- * @id: the cgroup id
- *
- * Returns the cgroup if there's valid one with @id, otherwise returns NULL.
- * Should be called under rcu_read_lock().
- */
-static inline struct cgroup *cgroup_from_id(struct cgroup_subsys *ss, int id)
-{
-#ifdef CONFIG_PROVE_RCU
-	rcu_lockdep_assert(rcu_read_lock_held() ||
-			   lockdep_is_held(&cgroup_mutex),
-			   "cgroup_from_id() needs proper protection");
-#endif
-	return idr_find(&ss->root->cgroup_idr, id);
-}
-
 struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
 					   struct cgroup_subsys_state *parent);
 
+struct cgroup_subsys_state *css_from_id(struct cgroup_subsys *ss, int id);
+
 /**
  * css_for_each_child - iterate through children of a css
  * @pos: the css * to use as the loop cursor

kernel/cgroup.c +22 -0

index 99785d6..6ec2377 100644
@@ -5710,6 +5710,28 @@ struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id)
 	return css ? css : ERR_PTR(-ENOENT);
 }
 
+/**
+ * css_from_id - lookup css by id
+ * @ss: cgroup subsys to be looked into
+ * @id: the cgroup id
+ *
+ * Returns the css if there's valid one with @id, otherwise returns NULL.
+ * Should be called under rcu_read_lock().
+ */
+struct cgroup_subsys_state *css_from_id(struct cgroup_subsys *ss, int id)
+{
+	struct cgroup *cgrp;
+
+	rcu_lockdep_assert(rcu_read_lock_held() ||
+			   lockdep_is_held(&cgroup_mutex),
+			   "css_from_id() needs proper protection");
+
+	cgrp = idr_find(&ss->root->cgroup_idr, id);
+	if (cgrp)
+		return cgroup_css(cgrp, ss->subsys_id);
+	return NULL;
+}
+
 #ifdef CONFIG_CGROUP_DEBUG
 static struct cgroup_subsys_state *
 debug_css_alloc(struct cgroup_subsys_state *parent_css)

Signature · 1 line

1.8.0.2

Tejun Heo

maintainer

2013-08-16 17:06 UTC #1 lore raw

Hello, Li.

kernel/cgroup.c struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id) · line 5721

Quoted 9 lines · Li Zefan

kernel/cgroup.c +9 -0

+/**
+ * css_from_id - lookup css by id
+ * @ss: cgroup subsys to be looked into
+ * @id: the cgroup id
+ *
+ * Returns the css if there's valid one with @id, otherwise returns NULL.
+ * Should be called under rcu_read_lock().
+ */
+struct cgroup_subsys_state *css_from_id(struct cgroup_subsys *ss, int id)

Can we please do css_from_id(int id, struct cgroup_subsys *ss) instead?

Thanks.

Signature · 1 line

tejun

Li Zefan

author

2013-08-19 02:05 UTC #2 lore raw

PATCH v2 1/1 cgroup: change cgroup_from_id() to css_from_id()

Now we want cgroup core to always provide the css to use to the subsystems, so change this API to css_from_id().

Uninline css_from_id(), because it's getting bigger and cgroup_css() has been unexported.

While at it, remove the #ifdef, and shuffle the order of the args.

Signed-off-by Li Zefan <[email protected]>

---

v2: change the order of the args.

---
 include/linux/cgroup.h | 20 ++------------------
 kernel/cgroup.c        | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 18 deletions(-)

include/linux/cgroup.h +2 ~~-18~~

index 11a6419..3aac34d 100644
@@ -742,27 +742,11 @@ static inline struct cgroup *task_cgroup(struct task_struct *task,
 	return task_css(task, subsys_id)->cgroup;
 }
 
-/**
- * cgroup_from_id - lookup cgroup by id
- * @ss: cgroup subsys to be looked into
- * @id: the cgroup id
- *
- * Returns the cgroup if there's valid one with @id, otherwise returns NULL.
- * Should be called under rcu_read_lock().
- */
-static inline struct cgroup *cgroup_from_id(struct cgroup_subsys *ss, int id)
-{
-#ifdef CONFIG_PROVE_RCU
-	rcu_lockdep_assert(rcu_read_lock_held() ||
-			   lockdep_is_held(&cgroup_mutex),
-			   "cgroup_from_id() needs proper protection");
-#endif
-	return idr_find(&ss->root->cgroup_idr, id);
-}
-
 struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
 					   struct cgroup_subsys_state *parent);
 
+struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss);
+
 /**
  * css_for_each_child - iterate through children of a css
  * @pos: the css * to use as the loop cursor

kernel/cgroup.c +22 -0

index 99785d6..07740d3 100644
@@ -5710,6 +5710,28 @@ struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id)
 	return css ? css : ERR_PTR(-ENOENT);
 }
 
+/**
+ * css_from_id - lookup css by id
+ * @id: the cgroup id
+ * @ss: cgroup subsys to be looked into
+ *
+ * Returns the css if there's valid one with @id, otherwise returns NULL.
+ * Should be called under rcu_read_lock().
+ */
+struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss)
+{
+	struct cgroup *cgrp;
+
+	rcu_lockdep_assert(rcu_read_lock_held() ||
+			   lockdep_is_held(&cgroup_mutex),
+			   "css_from_id() needs proper protection");
+
+	cgrp = idr_find(&ss->root->cgroup_idr, id);
+	if (cgrp)
+		return cgroup_css(cgrp, ss->subsys_id);
+	return NULL;
+}
+
 #ifdef CONFIG_CGROUP_DEBUG
 static struct cgroup_subsys_state *
 debug_css_alloc(struct cgroup_subsys_state *parent_css)

Signature · 1 line

1.8.0.2

Tejun Heo

maintainer Applied

2013-08-19 13:53 UTC #3 lore raw

Quoted 9 lines · Li Zefan

Now we want cgroup core to always provide the css to use to the subsystems, so change this API to css_from_id().
Uninline css_from_id(), because it's getting bigger and cgroup_css() has been unexported.
While at it, remove the #ifdef, and shuffle the order of the args.
Signed-off-by Li Zefan <[email protected]>

Applied to cgroup/for-3.12.

Thanks.

Signature · 1 line

tejun