linux/include/linux/cgroup.h
<<
>>
Prefs
   1#ifndef _LINUX_CGROUP_H
   2#define _LINUX_CGROUP_H
   3/*
   4 *  cgroup interface
   5 *
   6 *  Copyright (C) 2003 BULL SA
   7 *  Copyright (C) 2004-2006 Silicon Graphics, Inc.
   8 *
   9 */
  10
  11#include <linux/sched.h>
  12#include <linux/cpumask.h>
  13#include <linux/nodemask.h>
  14#include <linux/rcupdate.h>
  15#include <linux/cgroupstats.h>
  16#include <linux/prio_heap.h>
  17#include <linux/rwsem.h>
  18#include <linux/idr.h>
  19#include <linux/workqueue.h>
  20#include <linux/xattr.h>
  21
  22#ifdef CONFIG_CGROUPS
  23
  24struct cgroupfs_root;
  25struct cgroup_subsys;
  26struct inode;
  27struct cgroup;
  28struct css_id;
  29
  30extern int cgroup_init_early(void);
  31extern int cgroup_init(void);
  32extern void cgroup_lock(void);
  33extern int cgroup_lock_is_held(void);
  34extern bool cgroup_lock_live_group(struct cgroup *cgrp);
  35extern void cgroup_unlock(void);
  36extern void cgroup_fork(struct task_struct *p);
  37extern void cgroup_fork_callbacks(struct task_struct *p);
  38extern void cgroup_post_fork(struct task_struct *p);
  39extern void cgroup_exit(struct task_struct *p, int run_callbacks);
  40extern int cgroupstats_build(struct cgroupstats *stats,
  41                                struct dentry *dentry);
  42extern int cgroup_load_subsys(struct cgroup_subsys *ss);
  43extern void cgroup_unload_subsys(struct cgroup_subsys *ss);
  44
  45extern const struct file_operations proc_cgroup_operations;
  46
  47/* Define the enumeration of all builtin cgroup subsystems */
  48#define SUBSYS(_x) _x ## _subsys_id,
  49#define IS_SUBSYS_ENABLED(option) IS_ENABLED(option)
  50enum cgroup_subsys_id {
  51#include <linux/cgroup_subsys.h>
  52        CGROUP_SUBSYS_COUNT,
  53};
  54#undef IS_SUBSYS_ENABLED
  55#undef SUBSYS
  56
  57/* Per-subsystem/per-cgroup state maintained by the system. */
  58struct cgroup_subsys_state {
  59        /*
  60         * The cgroup that this subsystem is attached to. Useful
  61         * for subsystems that want to know about the cgroup
  62         * hierarchy structure
  63         */
  64        struct cgroup *cgroup;
  65
  66        /*
  67         * State maintained by the cgroup system to allow subsystems
  68         * to be "busy". Should be accessed via css_get(),
  69         * css_tryget() and and css_put().
  70         */
  71
  72        atomic_t refcnt;
  73
  74        unsigned long flags;
  75        /* ID for this css, if possible */
  76        struct css_id __rcu *id;
  77
  78        /* Used to put @cgroup->dentry on the last css_put() */
  79        struct work_struct dput_work;
  80};
  81
  82/* bits in struct cgroup_subsys_state flags field */
  83enum {
  84        CSS_ROOT, /* This CSS is the root of the subsystem */
  85        CSS_REMOVED, /* This CSS is dead */
  86        CSS_CLEAR_CSS_REFS,             /* @ss->__DEPRECATED_clear_css_refs */
  87};
  88
  89/* Caller must verify that the css is not for root cgroup */
  90static inline void __css_get(struct cgroup_subsys_state *css, int count)
  91{
  92        atomic_add(count, &css->refcnt);
  93}
  94
  95/*
  96 * Call css_get() to hold a reference on the css; it can be used
  97 * for a reference obtained via:
  98 * - an existing ref-counted reference to the css
  99 * - task->cgroups for a locked task
 100 */
 101
 102static inline void css_get(struct cgroup_subsys_state *css)
 103{
 104        /* We don't need to reference count the root state */
 105        if (!test_bit(CSS_ROOT, &css->flags))
 106                __css_get(css, 1);
 107}
 108
 109static inline bool css_is_removed(struct cgroup_subsys_state *css)
 110{
 111        return test_bit(CSS_REMOVED, &css->flags);
 112}
 113
 114/*
 115 * Call css_tryget() to take a reference on a css if your existing
 116 * (known-valid) reference isn't already ref-counted. Returns false if
 117 * the css has been destroyed.
 118 */
 119
 120extern bool __css_tryget(struct cgroup_subsys_state *css);
 121static inline bool css_tryget(struct cgroup_subsys_state *css)
 122{
 123        if (test_bit(CSS_ROOT, &css->flags))
 124                return true;
 125        return __css_tryget(css);
 126}
 127
 128/*
 129 * css_put() should be called to release a reference taken by
 130 * css_get() or css_tryget()
 131 */
 132
 133extern void __css_put(struct cgroup_subsys_state *css);
 134static inline void css_put(struct cgroup_subsys_state *css)
 135{
 136        if (!test_bit(CSS_ROOT, &css->flags))
 137                __css_put(css);
 138}
 139
 140/* bits in struct cgroup flags field */
 141enum {
 142        /* Control Group is dead */
 143        CGRP_REMOVED,
 144        /*
 145         * Control Group has previously had a child cgroup or a task,
 146         * but no longer (only if CGRP_NOTIFY_ON_RELEASE is set)
 147         */
 148        CGRP_RELEASABLE,
 149        /* Control Group requires release notifications to userspace */
 150        CGRP_NOTIFY_ON_RELEASE,
 151        /*
 152         * A thread in rmdir() is wating for this cgroup.
 153         */
 154        CGRP_WAIT_ON_RMDIR,
 155        /*
 156         * Clone cgroup values when creating a new child cgroup
 157         */
 158        CGRP_CLONE_CHILDREN,
 159};
 160
 161struct cgroup {
 162        unsigned long flags;            /* "unsigned long" so bitops work */
 163
 164        /*
 165         * count users of this cgroup. >0 means busy, but doesn't
 166         * necessarily indicate the number of tasks in the cgroup
 167         */
 168        atomic_t count;
 169
 170        /*
 171         * We link our 'sibling' struct into our parent's 'children'.
 172         * Our children link their 'sibling' into our 'children'.
 173         */
 174        struct list_head sibling;       /* my parent's children */
 175        struct list_head children;      /* my children */
 176        struct list_head files;         /* my files */
 177
 178        struct cgroup *parent;          /* my parent */
 179        struct dentry __rcu *dentry;    /* cgroup fs entry, RCU protected */
 180
 181        /* Private pointers for each registered subsystem */
 182        struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
 183
 184        struct cgroupfs_root *root;
 185        struct cgroup *top_cgroup;
 186
 187        /*
 188         * List of cg_cgroup_links pointing at css_sets with
 189         * tasks in this cgroup. Protected by css_set_lock
 190         */
 191        struct list_head css_sets;
 192
 193        struct list_head allcg_node;    /* cgroupfs_root->allcg_list */
 194        struct list_head cft_q_node;    /* used during cftype add/rm */
 195
 196        /*
 197         * Linked list running through all cgroups that can
 198         * potentially be reaped by the release agent. Protected by
 199         * release_list_lock
 200         */
 201        struct list_head release_list;
 202
 203        /*
 204         * list of pidlists, up to two for each namespace (one for procs, one
 205         * for tasks); created on demand.
 206         */
 207        struct list_head pidlists;
 208        struct mutex pidlist_mutex;
 209
 210        /* For RCU-protected deletion */
 211        struct rcu_head rcu_head;
 212
 213        /* List of events which userspace want to receive */
 214        struct list_head event_list;
 215        spinlock_t event_list_lock;
 216
 217        /* directory xattrs */
 218        struct simple_xattrs xattrs;
 219};
 220
 221/*
 222 * A css_set is a structure holding pointers to a set of
 223 * cgroup_subsys_state objects. This saves space in the task struct
 224 * object and speeds up fork()/exit(), since a single inc/dec and a
 225 * list_add()/del() can bump the reference count on the entire cgroup
 226 * set for a task.
 227 */
 228
 229struct css_set {
 230
 231        /* Reference count */
 232        atomic_t refcount;
 233
 234        /*
 235         * List running through all cgroup groups in the same hash
 236         * slot. Protected by css_set_lock
 237         */
 238        struct hlist_node hlist;
 239
 240        /*
 241         * List running through all tasks using this cgroup
 242         * group. Protected by css_set_lock
 243         */
 244        struct list_head tasks;
 245
 246        /*
 247         * List of cg_cgroup_link objects on link chains from
 248         * cgroups referenced from this css_set. Protected by
 249         * css_set_lock
 250         */
 251        struct list_head cg_links;
 252
 253        /*
 254         * Set of subsystem states, one for each subsystem. This array
 255         * is immutable after creation apart from the init_css_set
 256         * during subsystem registration (at boot time) and modular subsystem
 257         * loading/unloading.
 258         */
 259        struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
 260
 261        /* For RCU-protected deletion */
 262        struct rcu_head rcu_head;
 263};
 264
 265/*
 266 * cgroup_map_cb is an abstract callback API for reporting map-valued
 267 * control files
 268 */
 269
 270struct cgroup_map_cb {
 271        int (*fill)(struct cgroup_map_cb *cb, const char *key, u64 value);
 272        void *state;
 273};
 274
 275/*
 276 * struct cftype: handler definitions for cgroup control files
 277 *
 278 * When reading/writing to a file:
 279 *      - the cgroup to use is file->f_dentry->d_parent->d_fsdata
 280 *      - the 'cftype' of the file is file->f_dentry->d_fsdata
 281 */
 282
 283/* cftype->flags */
 284#define CFTYPE_ONLY_ON_ROOT     (1U << 0)       /* only create on root cg */
 285#define CFTYPE_NOT_ON_ROOT      (1U << 1)       /* don't create onp root cg */
 286
 287#define MAX_CFTYPE_NAME         64
 288
 289struct cftype {
 290        /*
 291         * By convention, the name should begin with the name of the
 292         * subsystem, followed by a period.  Zero length string indicates
 293         * end of cftype array.
 294         */
 295        char name[MAX_CFTYPE_NAME];
 296        int private;
 297        /*
 298         * If not 0, file mode is set to this value, otherwise it will
 299         * be figured out automatically
 300         */
 301        umode_t mode;
 302
 303        /*
 304         * If non-zero, defines the maximum length of string that can
 305         * be passed to write_string; defaults to 64
 306         */
 307        size_t max_write_len;
 308
 309        /* CFTYPE_* flags */
 310        unsigned int flags;
 311
 312        /* file xattrs */
 313        struct simple_xattrs xattrs;
 314
 315        int (*open)(struct inode *inode, struct file *file);
 316        ssize_t (*read)(struct cgroup *cgrp, struct cftype *cft,
 317                        struct file *file,
 318                        char __user *buf, size_t nbytes, loff_t *ppos);
 319        /*
 320         * read_u64() is a shortcut for the common case of returning a
 321         * single integer. Use it in place of read()
 322         */
 323        u64 (*read_u64)(struct cgroup *cgrp, struct cftype *cft);
 324        /*
 325         * read_s64() is a signed version of read_u64()
 326         */
 327        s64 (*read_s64)(struct cgroup *cgrp, struct cftype *cft);
 328        /*
 329         * read_map() is used for defining a map of key/value
 330         * pairs. It should call cb->fill(cb, key, value) for each
 331         * entry. The key/value pairs (and their ordering) should not
 332         * change between reboots.
 333         */
 334        int (*read_map)(struct cgroup *cont, struct cftype *cft,
 335                        struct cgroup_map_cb *cb);
 336        /*
 337         * read_seq_string() is used for outputting a simple sequence
 338         * using seqfile.
 339         */
 340        int (*read_seq_string)(struct cgroup *cont, struct cftype *cft,
 341                               struct seq_file *m);
 342
 343        ssize_t (*write)(struct cgroup *cgrp, struct cftype *cft,
 344                         struct file *file,
 345                         const char __user *buf, size_t nbytes, loff_t *ppos);
 346
 347        /*
 348         * write_u64() is a shortcut for the common case of accepting
 349         * a single integer (as parsed by simple_strtoull) from
 350         * userspace. Use in place of write(); return 0 or error.
 351         */
 352        int (*write_u64)(struct cgroup *cgrp, struct cftype *cft, u64 val);
 353        /*
 354         * write_s64() is a signed version of write_u64()
 355         */
 356        int (*write_s64)(struct cgroup *cgrp, struct cftype *cft, s64 val);
 357
 358        /*
 359         * write_string() is passed a nul-terminated kernelspace
 360         * buffer of maximum length determined by max_write_len.
 361         * Returns 0 or -ve error code.
 362         */
 363        int (*write_string)(struct cgroup *cgrp, struct cftype *cft,
 364                            const char *buffer);
 365        /*
 366         * trigger() callback can be used to get some kick from the
 367         * userspace, when the actual string written is not important
 368         * at all. The private field can be used to determine the
 369         * kick type for multiplexing.
 370         */
 371        int (*trigger)(struct cgroup *cgrp, unsigned int event);
 372
 373        int (*release)(struct inode *inode, struct file *file);
 374
 375        /*
 376         * register_event() callback will be used to add new userspace
 377         * waiter for changes related to the cftype. Implement it if
 378         * you want to provide this functionality. Use eventfd_signal()
 379         * on eventfd to send notification to userspace.
 380         */
 381        int (*register_event)(struct cgroup *cgrp, struct cftype *cft,
 382                        struct eventfd_ctx *eventfd, const char *args);
 383        /*
 384         * unregister_event() callback will be called when userspace
 385         * closes the eventfd or on cgroup removing.
 386         * This callback must be implemented, if you want provide
 387         * notification functionality.
 388         */
 389        void (*unregister_event)(struct cgroup *cgrp, struct cftype *cft,
 390                        struct eventfd_ctx *eventfd);
 391};
 392
 393/*
 394 * cftype_sets describe cftypes belonging to a subsystem and are chained at
 395 * cgroup_subsys->cftsets.  Each cftset points to an array of cftypes
 396 * terminated by zero length name.
 397 */
 398struct cftype_set {
 399        struct list_head                node;   /* chained at subsys->cftsets */
 400        struct cftype                   *cfts;
 401};
 402
 403struct cgroup_scanner {
 404        struct cgroup *cg;
 405        int (*test_task)(struct task_struct *p, struct cgroup_scanner *scan);
 406        void (*process_task)(struct task_struct *p,
 407                        struct cgroup_scanner *scan);
 408        struct ptr_heap *heap;
 409        void *data;
 410};
 411
 412int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
 413int cgroup_rm_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
 414
 415int cgroup_is_removed(const struct cgroup *cgrp);
 416
 417int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen);
 418
 419int cgroup_task_count(const struct cgroup *cgrp);
 420
 421/* Return true if cgrp is a descendant of the task's cgroup */
 422int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task);
 423
 424/*
 425 * When the subsys has to access css and may add permanent refcnt to css,
 426 * it should take care of racy conditions with rmdir(). Following set of
 427 * functions, is for stop/restart rmdir if necessary.
 428 * Because these will call css_get/put, "css" should be alive css.
 429 *
 430 *  cgroup_exclude_rmdir();
 431 *  ...do some jobs which may access arbitrary empty cgroup
 432 *  cgroup_release_and_wakeup_rmdir();
 433 *
 434 *  When someone removes a cgroup while cgroup_exclude_rmdir() holds it,
 435 *  it sleeps and cgroup_release_and_wakeup_rmdir() will wake him up.
 436 */
 437
 438void cgroup_exclude_rmdir(struct cgroup_subsys_state *css);
 439void cgroup_release_and_wakeup_rmdir(struct cgroup_subsys_state *css);
 440
 441/*
 442 * Control Group taskset, used to pass around set of tasks to cgroup_subsys
 443 * methods.
 444 */
 445struct cgroup_taskset;
 446struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset);
 447struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset);
 448struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset);
 449int cgroup_taskset_size(struct cgroup_taskset *tset);
 450
 451/**
 452 * cgroup_taskset_for_each - iterate cgroup_taskset
 453 * @task: the loop cursor
 454 * @skip_cgrp: skip if task's cgroup matches this, %NULL to iterate through all
 455 * @tset: taskset to iterate
 456 */
 457#define cgroup_taskset_for_each(task, skip_cgrp, tset)                  \
 458        for ((task) = cgroup_taskset_first((tset)); (task);             \
 459             (task) = cgroup_taskset_next((tset)))                      \
 460                if (!(skip_cgrp) ||                                     \
 461                    cgroup_taskset_cur_cgroup((tset)) != (skip_cgrp))
 462
 463/*
 464 * Control Group subsystem type.
 465 * See Documentation/cgroups/cgroups.txt for details
 466 */
 467
 468struct cgroup_subsys {
 469        struct cgroup_subsys_state *(*create)(struct cgroup *cgrp);
 470        int (*pre_destroy)(struct cgroup *cgrp);
 471        void (*destroy)(struct cgroup *cgrp);
 472        int (*can_attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);
 473        void (*cancel_attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);
 474        void (*attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);
 475        void (*fork)(struct task_struct *task);
 476        void (*exit)(struct cgroup *cgrp, struct cgroup *old_cgrp,
 477                     struct task_struct *task);
 478        void (*post_clone)(struct cgroup *cgrp);
 479        void (*bind)(struct cgroup *root);
 480
 481        int subsys_id;
 482        int active;
 483        int disabled;
 484        int early_init;
 485        /*
 486         * True if this subsys uses ID. ID is not available before cgroup_init()
 487         * (not available in early_init time.)
 488         */
 489        bool use_id;
 490
 491        /*
 492         * If %true, cgroup removal will try to clear css refs by retrying
 493         * ss->pre_destroy() until there's no css ref left.  This behavior
 494         * is strictly for backward compatibility and will be removed as
 495         * soon as the current user (memcg) is updated.
 496         *
 497         * If %false, ss->pre_destroy() can't fail and cgroup removal won't
 498         * wait for css refs to drop to zero before proceeding.
 499         */
 500        bool __DEPRECATED_clear_css_refs;
 501
 502        /*
 503         * If %false, this subsystem is properly hierarchical -
 504         * configuration, resource accounting and restriction on a parent
 505         * cgroup cover those of its children.  If %true, hierarchy support
 506         * is broken in some ways - some subsystems ignore hierarchy
 507         * completely while others are only implemented half-way.
 508         *
 509         * It's now disallowed to create nested cgroups if the subsystem is
 510         * broken and cgroup core will emit a warning message on such
 511         * cases.  Eventually, all subsystems will be made properly
 512         * hierarchical and this will go away.
 513         */
 514        bool broken_hierarchy;
 515        bool warned_broken_hierarchy;
 516
 517#define MAX_CGROUP_TYPE_NAMELEN 32
 518        const char *name;
 519
 520        /*
 521         * Link to parent, and list entry in parent's children.
 522         * Protected by cgroup_lock()
 523         */
 524        struct cgroupfs_root *root;
 525        struct list_head sibling;
 526        /* used when use_id == true */
 527        struct idr idr;
 528        spinlock_t id_lock;
 529
 530        /* list of cftype_sets */
 531        struct list_head cftsets;
 532
 533        /* base cftypes, automatically [de]registered with subsys itself */
 534        struct cftype *base_cftypes;
 535        struct cftype_set base_cftset;
 536
 537        /* should be defined only by modular subsystems */
 538        struct module *module;
 539};
 540
 541#define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys;
 542#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option)
 543#include <linux/cgroup_subsys.h>
 544#undef IS_SUBSYS_ENABLED
 545#undef SUBSYS
 546
 547static inline struct cgroup_subsys_state *cgroup_subsys_state(
 548        struct cgroup *cgrp, int subsys_id)
 549{
 550        return cgrp->subsys[subsys_id];
 551}
 552
 553/*
 554 * function to get the cgroup_subsys_state which allows for extra
 555 * rcu_dereference_check() conditions, such as locks used during the
 556 * cgroup_subsys::attach() methods.
 557 */
 558#define task_subsys_state_check(task, subsys_id, __c)                   \
 559        rcu_dereference_check(task->cgroups->subsys[subsys_id],         \
 560                              lockdep_is_held(&task->alloc_lock) ||     \
 561                              cgroup_lock_is_held() || (__c))
 562
 563static inline struct cgroup_subsys_state *
 564task_subsys_state(struct task_struct *task, int subsys_id)
 565{
 566        return task_subsys_state_check(task, subsys_id, false);
 567}
 568
 569static inline struct cgroup* task_cgroup(struct task_struct *task,
 570                                               int subsys_id)
 571{
 572        return task_subsys_state(task, subsys_id)->cgroup;
 573}
 574
 575/* A cgroup_iter should be treated as an opaque object */
 576struct cgroup_iter {
 577        struct list_head *cg_link;
 578        struct list_head *task;
 579};
 580
 581/*
 582 * To iterate across the tasks in a cgroup:
 583 *
 584 * 1) call cgroup_iter_start to initialize an iterator
 585 *
 586 * 2) call cgroup_iter_next() to retrieve member tasks until it
 587 *    returns NULL or until you want to end the iteration
 588 *
 589 * 3) call cgroup_iter_end() to destroy the iterator.
 590 *
 591 * Or, call cgroup_scan_tasks() to iterate through every task in a
 592 * cgroup - cgroup_scan_tasks() holds the css_set_lock when calling
 593 * the test_task() callback, but not while calling the process_task()
 594 * callback.
 595 */
 596void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it);
 597struct task_struct *cgroup_iter_next(struct cgroup *cgrp,
 598                                        struct cgroup_iter *it);
 599void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it);
 600int cgroup_scan_tasks(struct cgroup_scanner *scan);
 601int cgroup_attach_task(struct cgroup *, struct task_struct *);
 602int cgroup_attach_task_all(struct task_struct *from, struct task_struct *);
 603
 604/*
 605 * CSS ID is ID for cgroup_subsys_state structs under subsys. This only works
 606 * if cgroup_subsys.use_id == true. It can be used for looking up and scanning.
 607 * CSS ID is assigned at cgroup allocation (create) automatically
 608 * and removed when subsys calls free_css_id() function. This is because
 609 * the lifetime of cgroup_subsys_state is subsys's matter.
 610 *
 611 * Looking up and scanning function should be called under rcu_read_lock().
 612 * Taking cgroup_mutex is not necessary for following calls.
 613 * But the css returned by this routine can be "not populated yet" or "being
 614 * destroyed". The caller should check css and cgroup's status.
 615 */
 616
 617/*
 618 * Typically Called at ->destroy(), or somewhere the subsys frees
 619 * cgroup_subsys_state.
 620 */
 621void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css);
 622
 623/* Find a cgroup_subsys_state which has given ID */
 624
 625struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id);
 626
 627/*
 628 * Get a cgroup whose id is greater than or equal to id under tree of root.
 629 * Returning a cgroup_subsys_state or NULL.
 630 */
 631struct cgroup_subsys_state *css_get_next(struct cgroup_subsys *ss, int id,
 632                struct cgroup_subsys_state *root, int *foundid);
 633
 634/* Returns true if root is ancestor of cg */
 635bool css_is_ancestor(struct cgroup_subsys_state *cg,
 636                     const struct cgroup_subsys_state *root);
 637
 638/* Get id and depth of css */
 639unsigned short css_id(struct cgroup_subsys_state *css);
 640unsigned short css_depth(struct cgroup_subsys_state *css);
 641struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id);
 642
 643#else /* !CONFIG_CGROUPS */
 644
 645static inline int cgroup_init_early(void) { return 0; }
 646static inline int cgroup_init(void) { return 0; }
 647static inline void cgroup_fork(struct task_struct *p) {}
 648static inline void cgroup_fork_callbacks(struct task_struct *p) {}
 649static inline void cgroup_post_fork(struct task_struct *p) {}
 650static inline void cgroup_exit(struct task_struct *p, int callbacks) {}
 651
 652static inline void cgroup_lock(void) {}
 653static inline void cgroup_unlock(void) {}
 654static inline int cgroupstats_build(struct cgroupstats *stats,
 655                                        struct dentry *dentry)
 656{
 657        return -EINVAL;
 658}
 659
 660/* No cgroups - nothing to do */
 661static inline int cgroup_attach_task_all(struct task_struct *from,
 662                                         struct task_struct *t)
 663{
 664        return 0;
 665}
 666
 667#endif /* !CONFIG_CGROUPS */
 668
 669#endif /* _LINUX_CGROUP_H */
 670
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.