*/
#include <linux/sched.h>
-#include <linux/kref.h>
#include <linux/cpumask.h>
#include <linux/nodemask.h>
#include <linux/rcupdate.h>
+#include <linux/cgroupstats.h>
+#include <linux/prio_heap.h>
+#include <linux/rwsem.h>
#ifdef CONFIG_CGROUPS
struct cgroupfs_root;
struct cgroup_subsys;
struct inode;
+struct cgroup;
extern int cgroup_init_early(void);
extern int cgroup_init(void);
extern void cgroup_init_smp(void);
extern void cgroup_lock(void);
+extern bool cgroup_lock_live_group(struct cgroup *cgrp);
extern void cgroup_unlock(void);
extern void cgroup_fork(struct task_struct *p);
extern void cgroup_fork_callbacks(struct task_struct *p);
+extern void cgroup_post_fork(struct task_struct *p);
extern void cgroup_exit(struct task_struct *p, int run_callbacks);
+extern int cgroupstats_build(struct cgroupstats *stats,
+ struct dentry *dentry);
+
+extern struct file_operations proc_cgroup_operations;
+
+/* Define the enumeration of all cgroup subsystems */
+#define SUBSYS(_x) _x ## _subsys_id,
+enum cgroup_subsys_id {
+#include <linux/cgroup_subsys.h>
+ CGROUP_SUBSYS_COUNT
+};
+#undef SUBSYS
/* Per-subsystem/per-cgroup state maintained by the system. */
struct cgroup_subsys_state {
* css_get()
*/
+extern void __css_put(struct cgroup_subsys_state *css);
static inline void css_put(struct cgroup_subsys_state *css)
{
if (!test_bit(CSS_ROOT, &css->flags))
- atomic_dec(&css->refcnt);
+ __css_put(css);
}
+/* bits in struct cgroup flags field */
+enum {
+ /* Control Group is dead */
+ CGRP_REMOVED,
+ /* Control Group has previously had a child cgroup or a task,
+ * but no longer (only if CGRP_NOTIFY_ON_RELEASE is set) */
+ CGRP_RELEASABLE,
+ /* Control Group requires release notifications to userspace */
+ CGRP_NOTIFY_ON_RELEASE,
+};
+
struct cgroup {
unsigned long flags; /* "unsigned long" so bitops work */
struct cgroupfs_root *root;
struct cgroup *top_cgroup;
+
+ /*
+ * List of cg_cgroup_links pointing at css_sets with
+ * tasks in this cgroup. Protected by css_set_lock
+ */
+ struct list_head css_sets;
+
+ /*
+ * Linked list running through all cgroups that can
+ * potentially be reaped by the release agent. Protected by
+ * release_list_lock
+ */
+ struct list_head release_list;
+
+ /* pids_mutex protects the fields below */
+ struct rw_semaphore pids_mutex;
+ /* Array of process ids in the cgroup */
+ pid_t *tasks_pids;
+ /* How many files are using the current tasks_pids array */
+ int pids_use_count;
+ /* Length of the current tasks_pids array */
+ int pids_length;
+};
+
+/* A css_set is a structure holding pointers to a set of
+ * cgroup_subsys_state objects. This saves space in the task struct
+ * object and speeds up fork()/exit(), since a single inc/dec and a
+ * list_add()/del() can bump the reference count on the entire
+ * cgroup set for a task.
+ */
+
+struct css_set {
+
+ /* Reference count */
+ atomic_t refcount;
+
+ /*
+ * List running through all cgroup groups in the same hash
+ * slot. Protected by css_set_lock
+ */
+ struct hlist_node hlist;
+
+ /*
+ * List running through all tasks using this cgroup
+ * group. Protected by css_set_lock
+ */
+ struct list_head tasks;
+
+ /*
+ * List of cg_cgroup_link objects on link chains from
+ * cgroups referenced from this css_set. Protected by
+ * css_set_lock
+ */
+ struct list_head cg_links;
+
+ /*
+ * Set of subsystem states, one for each subsystem. This array
+ * is immutable after creation apart from the init_css_set
+ * during subsystem registration (at boot time).
+ */
+ struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
+};
+
+/*
+ * cgroup_map_cb is an abstract callback API for reporting map-valued
+ * control files
+ */
+
+struct cgroup_map_cb {
+ int (*fill)(struct cgroup_map_cb *cb, const char *key, u64 value);
+ void *state;
};
/* struct cftype:
*
*
* When reading/writing to a file:
- * - the cgroup to use in file->f_dentry->d_parent->d_fsdata
+ * - the cgroup to use is file->f_dentry->d_parent->d_fsdata
* - the 'cftype' of the file is file->f_dentry->d_fsdata
*/
* subsystem, followed by a period */
char name[MAX_CFTYPE_NAME];
int private;
- int (*open) (struct inode *inode, struct file *file);
- ssize_t (*read) (struct cgroup *cont, struct cftype *cft,
- struct file *file,
- char __user *buf, size_t nbytes, loff_t *ppos);
+
+ /*
+ * If non-zero, defines the maximum length of string that can
+ * be passed to write_string; defaults to 64
+ */
+ size_t max_write_len;
+
+ int (*open)(struct inode *inode, struct file *file);
+ ssize_t (*read)(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ char __user *buf, size_t nbytes, loff_t *ppos);
/*
- * read_uint() is a shortcut for the common case of returning a
+ * read_u64() is a shortcut for the common case of returning a
* single integer. Use it in place of read()
*/
- u64 (*read_uint) (struct cgroup *cont, struct cftype *cft);
- ssize_t (*write) (struct cgroup *cont, struct cftype *cft,
- struct file *file,
- const char __user *buf, size_t nbytes, loff_t *ppos);
+ u64 (*read_u64)(struct cgroup *cgrp, struct cftype *cft);
+ /*
+ * read_s64() is a signed version of read_u64()
+ */
+ s64 (*read_s64)(struct cgroup *cgrp, struct cftype *cft);
+ /*
+ * read_map() is used for defining a map of key/value
+ * pairs. It should call cb->fill(cb, key, value) for each
+ * entry. The key/value pairs (and their ordering) should not
+ * change between reboots.
+ */
+ int (*read_map)(struct cgroup *cont, struct cftype *cft,
+ struct cgroup_map_cb *cb);
+ /*
+ * read_seq_string() is used for outputting a simple sequence
+ * using seqfile.
+ */
+ int (*read_seq_string)(struct cgroup *cont, struct cftype *cft,
+ struct seq_file *m);
+
+ ssize_t (*write)(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ const char __user *buf, size_t nbytes, loff_t *ppos);
/*
- * write_uint() is a shortcut for the common case of accepting
+ * write_u64() is a shortcut for the common case of accepting
* a single integer (as parsed by simple_strtoull) from
* userspace. Use in place of write(); return 0 or error.
*/
- int (*write_uint) (struct cgroup *cont, struct cftype *cft, u64 val);
+ int (*write_u64)(struct cgroup *cgrp, struct cftype *cft, u64 val);
+ /*
+ * write_s64() is a signed version of write_u64()
+ */
+ int (*write_s64)(struct cgroup *cgrp, struct cftype *cft, s64 val);
- int (*release) (struct inode *inode, struct file *file);
+ /*
+ * write_string() is passed a nul-terminated kernelspace
+ * buffer of maximum length determined by max_write_len.
+ * Returns 0 or -ve error code.
+ */
+ int (*write_string)(struct cgroup *cgrp, struct cftype *cft,
+ const char *buffer);
+ /*
+ * trigger() callback can be used to get some kick from the
+ * userspace, when the actual string written is not important
+ * at all. The private field can be used to determine the
+ * kick type for multiplexing.
+ */
+ int (*trigger)(struct cgroup *cgrp, unsigned int event);
+
+ int (*release)(struct inode *inode, struct file *file);
+};
+
+struct cgroup_scanner {
+ struct cgroup *cg;
+ int (*test_task)(struct task_struct *p, struct cgroup_scanner *scan);
+ void (*process_task)(struct task_struct *p,
+ struct cgroup_scanner *scan);
+ struct ptr_heap *heap;
};
/* Add a new file to the given cgroup directory. Should only be
* called by subsystems from within a populate() method */
-int cgroup_add_file(struct cgroup *cont, struct cgroup_subsys *subsys,
+int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys,
const struct cftype *cft);
/* Add a set of new files to the given cgroup directory. Should
* only be called by subsystems from within a populate() method */
-int cgroup_add_files(struct cgroup *cont,
+int cgroup_add_files(struct cgroup *cgrp,
struct cgroup_subsys *subsys,
const struct cftype cft[],
int count);
-int cgroup_is_removed(const struct cgroup *cont);
+int cgroup_is_removed(const struct cgroup *cgrp);
-int cgroup_path(const struct cgroup *cont, char *buf, int buflen);
+int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen);
-int __cgroup_task_count(const struct cgroup *cont);
-static inline int cgroup_task_count(const struct cgroup *cont)
-{
- int task_count;
- rcu_read_lock();
- task_count = __cgroup_task_count(cont);
- rcu_read_unlock();
- return task_count;
-}
+int cgroup_task_count(const struct cgroup *cgrp);
/* Return true if the cgroup is a descendant of the current cgroup */
-int cgroup_is_descendant(const struct cgroup *cont);
+int cgroup_is_descendant(const struct cgroup *cgrp);
/* Control Group subsystem type. See Documentation/cgroups.txt for details */
struct cgroup_subsys {
struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss,
- struct cgroup *cont);
- void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cont);
+ struct cgroup *cgrp);
+ void (*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 *cont, struct task_struct *tsk);
- void (*attach)(struct cgroup_subsys *ss, struct cgroup *cont,
- struct cgroup *old_cont, struct task_struct *tsk);
+ struct cgroup *cgrp, struct task_struct *tsk);
+ void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct cgroup *old_cgrp, struct task_struct *tsk);
void (*fork)(struct cgroup_subsys *ss, struct task_struct *task);
void (*exit)(struct cgroup_subsys *ss, struct task_struct *task);
int (*populate)(struct cgroup_subsys *ss,
- struct cgroup *cont);
- void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cont);
+ struct cgroup *cgrp);
+ void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp);
void (*bind)(struct cgroup_subsys *ss, struct cgroup *root);
+ /*
+ * This routine is called with the task_lock of mm->owner held
+ */
+ void (*mm_owner_changed)(struct cgroup_subsys *ss,
+ struct cgroup *old,
+ struct cgroup *new,
+ struct task_struct *p);
int subsys_id;
int active;
+ int disabled;
int early_init;
#define MAX_CGROUP_TYPE_NAMELEN 32
const char *name;
#undef SUBSYS
static inline struct cgroup_subsys_state *cgroup_subsys_state(
- struct cgroup *cont, int subsys_id)
+ struct cgroup *cgrp, int subsys_id)
{
- return cont->subsys[subsys_id];
+ return cgrp->subsys[subsys_id];
}
static inline struct cgroup_subsys_state *task_subsys_state(
struct task_struct *task, int subsys_id)
{
- return rcu_dereference(task->cgroups.subsys[subsys_id]);
+ return rcu_dereference(task->cgroups->subsys[subsys_id]);
}
static inline struct cgroup* task_cgroup(struct task_struct *task,
return task_subsys_state(task, subsys_id)->cgroup;
}
-int cgroup_path(const struct cgroup *cont, char *buf, int buflen);
+int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *ss,
+ char *nodename);
+
+/* A cgroup_iter should be treated as an opaque object */
+struct cgroup_iter {
+ struct list_head *cg_link;
+ struct list_head *task;
+};
-int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *ss);
+/* To iterate across the tasks in a cgroup:
+ *
+ * 1) call cgroup_iter_start to intialize an iterator
+ *
+ * 2) call cgroup_iter_next() to retrieve member tasks until it
+ * returns NULL or until you want to end the iteration
+ *
+ * 3) call cgroup_iter_end() to destroy the iterator.
+ *
+ * Or, call cgroup_scan_tasks() to iterate through every task in a cpuset.
+ * - cgroup_scan_tasks() holds the css_set_lock when calling the test_task()
+ * callback, but not while calling the process_task() callback.
+ */
+void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it);
+struct task_struct *cgroup_iter_next(struct cgroup *cgrp,
+ struct cgroup_iter *it);
+void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it);
+int cgroup_scan_tasks(struct cgroup_scanner *scan);
+int cgroup_attach_task(struct cgroup *, struct task_struct *);
#else /* !CONFIG_CGROUPS */
static inline void cgroup_init_smp(void) {}
static inline void cgroup_fork(struct task_struct *p) {}
static inline void cgroup_fork_callbacks(struct task_struct *p) {}
+static inline void cgroup_post_fork(struct task_struct *p) {}
static inline void cgroup_exit(struct task_struct *p, int callbacks) {}
static inline void cgroup_lock(void) {}
static inline void cgroup_unlock(void) {}
+static inline int cgroupstats_build(struct cgroupstats *stats,
+ struct dentry *dentry)
+{
+ return -EINVAL;
+}
#endif /* !CONFIG_CGROUPS */
+#ifdef CONFIG_MM_OWNER
+extern void
+cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new);
+#else /* !CONFIG_MM_OWNER */
+static inline void
+cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new)
+{
+}
+#endif /* CONFIG_MM_OWNER */
#endif /* _LINUX_CGROUP_H */