diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cgroup.h | 214 | ||||
| -rw-r--r-- | include/linux/cgroup_subsys.h | 10 | ||||
| -rw-r--r-- | include/linux/magic.h | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 34 |
4 files changed, 258 insertions, 1 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h new file mode 100644 index 000000000000..60735dcf427a --- /dev/null +++ b/include/linux/cgroup.h @@ -0,0 +1,214 @@ +#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> + +#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); + +/* 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() + */ + +static inline void css_put(struct cgroup_subsys_state *css) +{ + if (!test_bit(CSS_ROOT, &css->flags)) + atomic_dec(&css->refcnt); +} + +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; +}; + +/* 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); + 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); + +/* 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 (*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); + +#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_lock(void) {} +static inline void cgroup_unlock(void) {} + +#endif /* !CONFIG_CGROUPS */ + +#endif /* _LINUX_CGROUP_H */ diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h new file mode 100644 index 000000000000..f8eddbbcad9a --- /dev/null +++ b/include/linux/cgroup_subsys.h @@ -0,0 +1,10 @@ +/* Add subsystem definitions of the form SUBSYS(<name>) in this + * file. Surround each one by a line of comment markers so that + * patches don't collide + */ + +/* */ + +/* */ + +/* */ diff --git a/include/linux/magic.h b/include/linux/magic.h index 722d4755060f..1fa0c2ce4dec 100644 --- a/include/linux/magic.h +++ b/include/linux/magic.h @@ -37,6 +37,7 @@ #define SMB_SUPER_MAGIC 0x517B #define USBDEVICE_SUPER_MAGIC 0x9fa2 +#define CGROUP_SUPER_MAGIC 0x27e0eb #define FUTEXFS_SUPER_MAGIC 0xBAD1DEA #define INOTIFYFS_SUPER_MAGIC 0x2BAD1DEA diff --git a/include/linux/sched.h b/include/linux/sched.h index 10a83d8d5775..af2ed4bae678 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -894,6 +894,34 @@ struct sched_entity { #endif }; +#ifdef CONFIG_CGROUPS + +#define SUBSYS(_x) _x ## _subsys_id, +enum cgroup_subsys_id { +#include <linux/cgroup_subsys.h> + CGROUP_SUBSYS_COUNT +}; +#undef SUBSYS + +/* A css_set is a structure holding pointers to a set of + * cgroup_subsys_state objects. + */ + +struct css_set { + + /* Set of subsystem states, one for each subsystem. NULL for + * subsystems that aren't part of this hierarchy. These + * pointers reduce the number of dereferences required to get + * from a task to its state for a given cgroup, but result + * in increased space usage if tasks are in wildly different + * groupings across different hierarchies. This array is + * immutable after creation */ + struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; + +}; + +#endif /* CONFIG_CGROUPS */ + struct task_struct { volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */ void *stack; @@ -1130,6 +1158,9 @@ struct task_struct { int cpuset_mems_generation; int cpuset_mem_spread_rotor; #endif +#ifdef CONFIG_CGROUPS + struct css_set cgroups; +#endif #ifdef CONFIG_FUTEX struct robust_list_head __user *robust_list; #ifdef CONFIG_COMPAT @@ -1625,7 +1656,8 @@ static inline int thread_group_empty(struct task_struct *p) /* * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring * subscriptions and synchronises with wait4(). Also used in procfs. Also - * pins the final release of task.io_context. Also protects ->cpuset. + * pins the final release of task.io_context. Also protects ->cpuset and + * ->cgroup.subsys[]. * * Nests both inside and outside of read_lock(&tasklist_lock). * It must not be nested with write_lock_irq(&tasklist_lock), |