| #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> |
| #include <linux/prio_heap.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); |
| } |
| |
| /* 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 */ |
| |
| /* 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 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: |
| * |
| * 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 is 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 *cgrp, struct cftype *cft, |
| struct file *file, |
| char __user *buf, size_t nbytes, loff_t *ppos); |
| /* |
| * read_u64() is a shortcut for the common case of returning a |
| * single integer. Use it in place of read() |
| */ |
| 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); |
| |
| ssize_t (*write) (struct cgroup *cgrp, struct cftype *cft, |
| struct file *file, |
| const char __user *buf, size_t nbytes, loff_t *ppos); |
| |
| /* |
| * 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_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); |
| |
| /* |
| * 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 *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 *cgrp, |
| struct cgroup_subsys *subsys, |
| const struct cftype cft[], |
| int count); |
| |
| int cgroup_is_removed(const struct cgroup *cgrp); |
| |
| int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen); |
| |
| 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 *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 *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 *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 *cgrp); |
| void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp); |
| void (*bind)(struct cgroup_subsys *ss, struct cgroup *root); |
| int subsys_id; |
| int active; |
| int disabled; |
| 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 *cgrp, int 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]); |
| } |
| |
| static inline struct cgroup* task_cgroup(struct task_struct *task, |
| int subsys_id) |
| { |
| return task_subsys_state(task, subsys_id)->cgroup; |
| } |
| |
| 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. |
| * |
| * 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 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 */ |