Subversion Repositories test_project

#ifndef _LINUX_CGROUP_H

#define _LINUX_CGROUP_H

/*

 *  cgroup interface

 *

 *  Copyright (C) 2003 BULL SA

 *  Copyright (C) 2004-2006 Silicon Graphics, Inc.

 *

 */

#include <linux/sched.h>

#include <linux/kref.h>

#include <linux/cpumask.h>

#include <linux/nodemask.h>

#include <linux/rcupdate.h>

#include <linux/cgroupstats.h>

#ifdef CONFIG_CGROUPS

struct cgroupfs_root;

struct cgroup_subsys;

struct inode;

extern int cgroup_init_early(void);

extern int cgroup_init(void);

extern void cgroup_init_smp(void);

extern void cgroup_lock(void);

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 {

        /* The cgroup that this subsystem is attached to. Useful

         * for subsystems that want to know about the cgroup

         * hierarchy structure */

        struct cgroup *cgroup;

        /* State maintained by the cgroup system to allow

         * subsystems to be "busy". Should be accessed via css_get()

         * and css_put() */

        atomic_t refcnt;

        unsigned long flags;

};

/* bits in struct cgroup_subsys_state flags field */

enum {

        CSS_ROOT, /* This CSS is the root of the subsystem */

};

/*

 * Call css_get() to hold a reference on the cgroup;

 *

 */

static inline void css_get(struct cgroup_subsys_state *css)

{

        /* We don't need to reference count the root state */

        if (!test_bit(CSS_ROOT, &css->flags))

                atomic_inc(&css->refcnt);

}

/*

 * css_put() should be called to release a reference taken by

 * 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))

                __css_put(css);

}

struct cgroup {

        unsigned long flags;            /* "unsigned long" so bitops work */

        /* count users of this cgroup. >0 means busy, but doesn't

         * necessarily indicate the number of tasks in the

         * cgroup */

        atomic_t count;

        /*

         * We link our 'sibling' struct into our parent's 'children'.

         * Our children link their 'sibling' into our 'children'.

         */

        struct list_head sibling;       /* my parent's children */

        struct list_head children;      /* my children */

        struct cgroup *parent;  /* my parent */

        struct dentry *dentry;          /* cgroup fs entry */

        /* Private pointers for each registered subsystem */

        struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];

        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;

};

/* 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 */

        struct kref ref;

        /*

         * List running through all cgroup groups. Protected by

         * css_set_lock

         */

        struct list_head list;

        /*

         * 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];

};

/* struct cftype:

 *

 * The files in the cgroup filesystem mostly have a very simple read/write

 * handling, some common function will take care of it. Nevertheless some cases

 * (read tasks) are special and therefore I define this structure for every

 * kind of file.

 *

 *

 * When reading/writing to a file:

 *      - the cgroup to use in file->f_dentry->d_parent->d_fsdata

 *      - the 'cftype' of the file is file->f_dentry->d_fsdata

 */

#define MAX_CFTYPE_NAME 64

struct cftype {

        /* By convention, the name should begin with the name of the

         * 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);

        /*

         * read_uint() 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);

        /*

         * write_uint() 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 (*release) (struct inode *inode, struct file *file);

};

/* 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,

                       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,

                        struct cgroup_subsys *subsys,

                        const struct cftype cft[],

                        int count);

int cgroup_is_removed(const struct cgroup *cont);

int cgroup_path(const struct cgroup *cont, char *buf, int buflen);

int cgroup_task_count(const struct cgroup *cont);

/* Return true if the cgroup is a descendant of the current cgroup */

int cgroup_is_descendant(const struct cgroup *cont);

/* 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);

        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);

        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);

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

        int subsys_id;

        int active;

        int early_init;

#define MAX_CGROUP_TYPE_NAMELEN 32

        const char *name;

        /* Protected by RCU */

        struct cgroupfs_root *root;

        struct list_head sibling;

        void *private;

};

#define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys;

#include <linux/cgroup_subsys.h>

#undef SUBSYS

static inline struct cgroup_subsys_state *cgroup_subsys_state(

        struct cgroup *cont, int subsys_id)

{

        return cont->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]);

}

static inline struct cgroup* task_cgroup(struct task_struct *task,

                                               int subsys_id)

{

        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);

/* A cgroup_iter should be treated as an opaque object */

struct cgroup_iter {

        struct list_head *cg_link;

        struct list_head *task;

};

/* 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.

 */

void cgroup_iter_start(struct cgroup *cont, struct cgroup_iter *it);

struct task_struct *cgroup_iter_next(struct cgroup *cont,

                                        struct cgroup_iter *it);

void cgroup_iter_end(struct cgroup *cont, struct cgroup_iter *it);

#else /* !CONFIG_CGROUPS */

static inline int cgroup_init_early(void) { return 0; }

static inline int cgroup_init(void) { return 0; }

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 */

#endif /* _LINUX_CGROUP_H */