Commit 0d9cabdc authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup changes from Tejun Heo:
 "Out of the 8 commits, one fixes a long-standing locking issue around
  tasklist walking and others are cleanups."

* 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Walk task list under tasklist_lock in cgroup_enable_task_cg_list
  cgroup: Remove wrong comment on cgroup_enable_task_cg_list()
  cgroup: remove cgroup_subsys argument from callbacks
  cgroup: remove extra calls to find_existing_css_set
  cgroup: replace tasklist_lock with rcu_read_lock
  cgroup: simplify double-check locking in cgroup_attach_proc
  cgroup: move struct cgroup_pidlist out from the header file
  cgroup: remove cgroup_attach_task_current_cg()
parents 701085b2 3ce3230a

Documentation/cgroups/cgroups.txt

+11 −15
Original line number Diff line number Diff line
@@ -558,8 +558,7 @@ Each subsystem may export the following methods. The only mandatory 
methods are create/destroy. Any others that are null are presumed to

be successful no-ops.



struct cgroup_subsys_state *create(struct cgroup_subsys *ss,

				   struct cgroup *cgrp)

struct cgroup_subsys_state *create(struct cgroup *cgrp)

(cgroup_mutex held by caller)



Called to create a subsystem state object for a cgroup. The
@@ -574,7 +573,7 @@ identified by the passed cgroup object having a NULL parent (since 
it's the root of the hierarchy) and may be an appropriate place for

initialization code.



void destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)

void destroy(struct cgroup *cgrp)

(cgroup_mutex held by caller)



The cgroup system is about to destroy the passed cgroup; the subsystem
@@ -585,7 +584,7 @@ cgroup->parent is still valid. (Note - can also be called for a 
newly-created cgroup if an error occurs after this subsystem's

create() method has been called for the new cgroup).



int pre_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);

int pre_destroy(struct cgroup *cgrp);



Called before checking the reference count on each subsystem. This may

be useful for subsystems which have some extra references even if
@@ -593,8 +592,7 @@ there are not tasks in the cgroup. If pre_destroy() returns error code, 
rmdir() will fail with it. From this behavior, pre_destroy() can be

called multiple times against a cgroup.



int can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,

	       struct cgroup_taskset *tset)

int can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)

(cgroup_mutex held by caller)



Called prior to moving one or more tasks into a cgroup; if the
@@ -615,8 +613,7 @@ fork. If this method returns 0 (success) then this should remain valid 
while the caller holds cgroup_mutex and it is ensured that either

attach() or cancel_attach() will be called in future.



void cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,

		   struct cgroup_taskset *tset)

void cancel_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)

(cgroup_mutex held by caller)



Called when a task attach operation has failed after can_attach() has succeeded.
@@ -625,23 +622,22 @@ function, so that the subsystem can implement a rollback. If not, not necessary. 
This will be called only about subsystems whose can_attach() operation have

succeeded. The parameters are identical to can_attach().



void attach(struct cgroup_subsys *ss, struct cgroup *cgrp,

	    struct cgroup_taskset *tset)

void attach(struct cgroup *cgrp, struct cgroup_taskset *tset)

(cgroup_mutex held by caller)



Called after the task has been attached to the cgroup, to allow any

post-attachment activity that requires memory allocations or blocking.

The parameters are identical to can_attach().



void fork(struct cgroup_subsy *ss, struct task_struct *task)

void fork(struct task_struct *task)



Called when a task is forked into a cgroup.



void exit(struct cgroup_subsys *ss, struct task_struct *task)

void exit(struct task_struct *task)



Called during task exit.



int populate(struct cgroup_subsys *ss, struct cgroup *cgrp)

int populate(struct cgroup *cgrp)

(cgroup_mutex held by caller)



Called after creation of a cgroup to allow a subsystem to populate
@@ -651,7 +647,7 @@ include/linux/cgroup.h for details). Note that although this 
method can return an error code, the error code is currently not

always handled well.



void post_clone(struct cgroup_subsys *ss, struct cgroup *cgrp)

void post_clone(struct cgroup *cgrp)

(cgroup_mutex held by caller)



Called during cgroup_create() to do any parameter
@@ -659,7 +655,7 @@ initialization which might be required before a task could attach. For 
example in cpusets, no task may attach before 'cpus' and 'mems' are set

up.



void bind(struct cgroup_subsys *ss, struct cgroup *root)

void bind(struct cgroup *root)

(cgroup_mutex and ss->hierarchy_mutex held by caller)



Called when a cgroup subsystem is rebound to a different hierarchy

block/blk-cgroup.c

+8 −14
Original line number Diff line number Diff line
@@ -28,13 +28,10 @@ static LIST_HEAD(blkio_list); 
struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };

EXPORT_SYMBOL_GPL(blkio_root_cgroup);



static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,

						  struct cgroup *);

static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,

			      struct cgroup_taskset *);

static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,

			   struct cgroup_taskset *);

static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);

static struct cgroup_subsys_state *blkiocg_create(struct cgroup *);

static int blkiocg_can_attach(struct cgroup *, struct cgroup_taskset *);

static void blkiocg_attach(struct cgroup *, struct cgroup_taskset *);

static void blkiocg_destroy(struct cgroup *);

static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);



/* for encoding cft->private value on file */
@@ -1548,7 +1545,7 @@ static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) 
				ARRAY_SIZE(blkio_files));

}



static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)

static void blkiocg_destroy(struct cgroup *cgroup)

{

	struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);

	unsigned long flags;
@@ -1598,8 +1595,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) 
		kfree(blkcg);

}



static struct cgroup_subsys_state *

blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup)

static struct cgroup_subsys_state *blkiocg_create(struct cgroup *cgroup)

{

	struct blkio_cgroup *blkcg;

	struct cgroup *parent = cgroup->parent;
@@ -1628,8 +1624,7 @@ done: 
 * of the main cic data structures.  For now we allow a task to change

 * its cgroup only if it's the only owner of its ioc.

 */

static int blkiocg_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,

			      struct cgroup_taskset *tset)

static int blkiocg_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)

{

	struct task_struct *task;

	struct io_context *ioc;
@@ -1648,8 +1643,7 @@ static int blkiocg_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, 
	return ret;

}



static void blkiocg_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,

			   struct cgroup_taskset *tset)

static void blkiocg_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)

{

	struct task_struct *task;

	struct io_context *ioc;

include/linux/cgroup.h

+12 −58
Original line number Diff line number Diff line
@@ -160,38 +160,6 @@ enum { 
	CGRP_CLONE_CHILDREN,

};



/* which pidlist file are we talking about? */

enum cgroup_filetype {

	CGROUP_FILE_PROCS,

	CGROUP_FILE_TASKS,

};



/*

 * A pidlist is a list of pids that virtually represents the contents of one

 * of the cgroup files ("procs" or "tasks"). We keep a list of such pidlists,

 * a pair (one each for procs, tasks) for each pid namespace that's relevant

 * to the cgroup.

 */

struct cgroup_pidlist {

	/*

	 * used to find which pidlist is wanted. doesn't change as long as

	 * this particular list stays in the list.

	 */

	struct { enum cgroup_filetype type; struct pid_namespace *ns; } key;

	/* array of xids */

	pid_t *list;

	/* how many elements the above list has */

	int length;

	/* how many files are using the current array */

	int use_count;

	/* each of these stored in a list by its cgroup */

	struct list_head links;

	/* pointer to the cgroup we belong to, for list removal purposes */

	struct cgroup *owner;

	/* protects the other fields */

	struct rw_semaphore mutex;

};



struct cgroup {

	unsigned long flags;		/* "unsigned long" so bitops work */
@@ -484,23 +452,18 @@ int cgroup_taskset_size(struct cgroup_taskset *tset); 
 */



struct cgroup_subsys {

	struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss,

						  struct cgroup *cgrp);

	int (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);

	void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);

	int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,

			  struct cgroup_taskset *tset);

	void (*cancel_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,

			      struct cgroup_taskset *tset);

	void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,

		       struct cgroup_taskset *tset);

	void (*fork)(struct cgroup_subsys *ss, struct task_struct *task);

	void (*exit)(struct cgroup_subsys *ss, struct cgroup *cgrp,

			struct cgroup *old_cgrp, struct task_struct *task);

	int (*populate)(struct cgroup_subsys *ss,

			struct cgroup *cgrp);

	void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp);

	void (*bind)(struct cgroup_subsys *ss, struct cgroup *root);

	struct cgroup_subsys_state *(*create)(struct cgroup *cgrp);

	int (*pre_destroy)(struct cgroup *cgrp);

	void (*destroy)(struct cgroup *cgrp);

	int (*can_attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);

	void (*cancel_attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);

	void (*attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);

	void (*fork)(struct task_struct *task);

	void (*exit)(struct cgroup *cgrp, struct cgroup *old_cgrp,

		     struct task_struct *task);

	int (*populate)(struct cgroup_subsys *ss, struct cgroup *cgrp);

	void (*post_clone)(struct cgroup *cgrp);

	void (*bind)(struct cgroup *root);



	int subsys_id;

	int active;
@@ -602,11 +565,6 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan); 
int cgroup_attach_task(struct cgroup *, struct task_struct *);

int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);



static inline int cgroup_attach_task_current_cg(struct task_struct *tsk)

{

	return cgroup_attach_task_all(current, tsk);

}



/*

 * CSS ID is ID for cgroup_subsys_state structs under subsys. This only works

 * if cgroup_subsys.use_id == true. It can be used for looking up and scanning.
@@ -669,10 +627,6 @@ static inline int cgroup_attach_task_all(struct task_struct *from, 
{

	return 0;

}

static inline int cgroup_attach_task_current_cg(struct task_struct *t)

{

	return 0;

}



#endif /* !CONFIG_CGROUPS */

include/net/sock.h

+3 −4
Original line number Diff line number Diff line
@@ -69,7 +69,7 @@ struct cgroup; 
struct cgroup_subsys;

#ifdef CONFIG_NET

int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss);

void mem_cgroup_sockets_destroy(struct cgroup *cgrp, struct cgroup_subsys *ss);

void mem_cgroup_sockets_destroy(struct cgroup *cgrp);

#else

static inline

int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss)
@@ -77,7 +77,7 @@ int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss) 
	return 0;

}

static inline

void mem_cgroup_sockets_destroy(struct cgroup *cgrp, struct cgroup_subsys *ss)

void mem_cgroup_sockets_destroy(struct cgroup *cgrp)

{

}

#endif
@@ -871,8 +871,7 @@ struct proto { 
	 */

	int			(*init_cgroup)(struct cgroup *cgrp,

					       struct cgroup_subsys *ss);

	void			(*destroy_cgroup)(struct cgroup *cgrp,

						  struct cgroup_subsys *ss);

	void			(*destroy_cgroup)(struct cgroup *cgrp);

	struct cg_proto		*(*proto_cgroup)(struct mem_cgroup *memcg);

#endif

};

include/net/tcp_memcontrol.h

+1 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ struct tcp_memcontrol { 


struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg);

int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss);

void tcp_destroy_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss);

void tcp_destroy_cgroup(struct cgroup *cgrp);

unsigned long long tcp_max_memory(const struct mem_cgroup *memcg);

void tcp_prot_mem(struct mem_cgroup *memcg, long val, int idx);

#endif /* _TCP_MEMCG_H */

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