sh: convert /proc/cpu/aligmnent, /proc/cpu/kernel_alignment to seq_file

[safe/jmp/linux-2.6] / include / linux / cgroup.h

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 665fa70..0008dee 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -37,7 +37,7 @@ 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;
+extern const struct file_operations proc_cgroup_operations;
 
 /* Define the enumeration of all cgroup subsystems */
 #define SUBSYS(_x) _x ## _subsys_id,
@@ -141,6 +141,38 @@ enum {
        CGRP_WAIT_ON_RMDIR,
 };
 
+/* which pidlist file are we talking about? */
+enum cgroup_filetype {
+       CGROUP_FILE_PROCS,
+       CGROUP_FILE_TASKS,
+};
+
+/*
+ * A pidlist is a list of pids that virtually represents the contents of one
+ * of the cgroup files ("procs" or "tasks"). We keep a list of such pidlists,
+ * a pair (one each for procs, tasks) for each pid namespace that's relevant
+ * to the cgroup.
+ */
+struct cgroup_pidlist {
+       /*
+        * used to find which pidlist is wanted. doesn't change as long as
+        * this particular list stays in the list.
+        */
+       struct { enum cgroup_filetype type; struct pid_namespace *ns; } key;
+       /* array of xids */
+       pid_t *list;
+       /* how many elements the above list has */
+       int length;
+       /* how many files are using the current array */
+       int use_count;
+       /* each of these stored in a list by its cgroup */
+       struct list_head links;
+       /* pointer to the cgroup we belong to, for list removal purposes */
+       struct cgroup *owner;
+       /* protects the other fields */
+       struct rw_semaphore mutex;
+};
+
 struct cgroup {
        unsigned long flags;            /* "unsigned long" so bitops work */
 
@@ -179,14 +211,12 @@ struct cgroup {
         */
        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;
+       /*
+        * list of pidlists, up to two for each namespace (one for procs, one
+        * for tasks); created on demand.
+        */
+       struct list_head pidlists;
+       struct mutex pidlist_mutex;
 
        /* For RCU-protected deletion */
        struct rcu_head rcu_head;
@@ -230,6 +260,9 @@ struct css_set {
         * during subsystem registration (at boot time).
         */
        struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
+
+       /* For RCU-protected deletion */
+       struct rcu_head rcu_head;
 };
 
 /*
@@ -366,6 +399,23 @@ int cgroup_task_count(const struct cgroup *cgrp);
 int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task);
 
 /*
+ * When the subsys has to access css and may add permanent refcnt to css,
+ * it should take care of racy conditions with rmdir(). Following set of
+ * functions, is for stop/restart rmdir if necessary.
+ * Because these will call css_get/put, "css" should be alive css.
+ *
+ *  cgroup_exclude_rmdir();
+ *  ...do some jobs which may access arbitrary empty cgroup
+ *  cgroup_release_and_wakeup_rmdir();
+ *
+ *  When someone removes a cgroup while cgroup_exclude_rmdir() holds it,
+ *  it sleeps and cgroup_release_and_wakeup_rmdir() will wake him up.
+ */
+
+void cgroup_exclude_rmdir(struct cgroup_subsys_state *css);
+void cgroup_release_and_wakeup_rmdir(struct cgroup_subsys_state *css);
+
+/*
  * Control Group subsystem type.
  * See Documentation/cgroups/cgroups.txt for details
  */
@@ -375,10 +425,11 @@ struct cgroup_subsys {
                                                  struct cgroup *cgrp);
        int (*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);
+       int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
+                         struct task_struct *tsk, bool threadgroup);
        void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                       struct cgroup *old_cgrp, struct task_struct *tsk);
+                       struct cgroup *old_cgrp, struct task_struct *tsk,
+                       bool threadgroup);
        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,