Merge tag 'asm-generic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[karo-tx-linux.git] / include / linux / cgroup.h

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 355bf2ed886730be83611711339d587b4e41c85a..22e3754f89c511374af4ca8ac5a518786dcd6d88 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -13,7 +13,6 @@
 #include <linux/nodemask.h>
 #include <linux/rculist.h>
 #include <linux/cgroupstats.h>
-#include <linux/rwsem.h>
 #include <linux/fs.h>
 #include <linux/seq_file.h>
 #include <linux/kernfs.h>
@@ -42,6 +41,10 @@ struct css_task_iter {
        struct list_head                *task_pos;
        struct list_head                *tasks_head;
        struct list_head                *mg_tasks_head;
+
+       struct css_set                  *cur_cset;
+       struct task_struct              *cur_task;
+       struct list_head                iters_node;     /* css_set->task_iters */
 };
 
 extern struct cgroup_root cgrp_dfl_root;
@@ -99,6 +102,7 @@ extern void cgroup_cancel_fork(struct task_struct *p,
 extern void cgroup_post_fork(struct task_struct *p,
                             void *old_ss_priv[CGROUP_CANFORK_COUNT]);
 void cgroup_exit(struct task_struct *p);
+void cgroup_free(struct task_struct *p);
 
 int cgroup_init_early(void);
 int cgroup_init(void);
@@ -232,11 +236,33 @@ void css_task_iter_end(struct css_task_iter *it);
  * cgroup_taskset_for_each - iterate cgroup_taskset
  * @task: the loop cursor
  * @tset: taskset to iterate
+ *
+ * @tset may contain multiple tasks and they may belong to multiple
+ * processes.  When there are multiple tasks in @tset, if a task of a
+ * process is in @tset, all tasks of the process are in @tset.  Also, all
+ * are guaranteed to share the same source and destination csses.
+ *
+ * Iteration is not in any specific order.
  */
 #define cgroup_taskset_for_each(task, tset)                            \
        for ((task) = cgroup_taskset_first((tset)); (task);             \
             (task) = cgroup_taskset_next((tset)))
 
+/**
+ * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
+ * @leader: the loop cursor
+ * @tset: takset to iterate
+ *
+ * Iterate threadgroup leaders of @tset.  For single-task migrations, @tset
+ * may not contain any.
+ */
+#define cgroup_taskset_for_each_leader(leader, tset)                   \
+       for ((leader) = cgroup_taskset_first((tset)); (leader);         \
+            (leader) = cgroup_taskset_next((tset)))                    \
+               if ((leader) != (leader)->group_leader)                 \
+                       ;                                               \
+               else
+
 /*
  * Inline functions.
  */
@@ -341,11 +367,11 @@ static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
  */
 #ifdef CONFIG_PROVE_RCU
 extern struct mutex cgroup_mutex;
-extern struct rw_semaphore css_set_rwsem;
+extern spinlock_t css_set_lock;
 #define task_css_set_check(task, __c)                                  \
        rcu_dereference_check((task)->cgroups,                          \
                lockdep_is_held(&cgroup_mutex) ||                       \
-               lockdep_is_held(&css_set_rwsem) ||                      \
+               lockdep_is_held(&css_set_lock) ||                       \
                ((task)->flags & PF_EXITING) || (__c))
 #else
 #define task_css_set_check(task, __c)                                  \
@@ -434,9 +460,9 @@ static inline struct cgroup *task_cgroup(struct task_struct *task,
 }
 
 /* no synchronization, the result can only be used as a hint */
-static inline bool cgroup_has_tasks(struct cgroup *cgrp)
+static inline bool cgroup_is_populated(struct cgroup *cgrp)
 {
-       return !list_empty(&cgrp->cset_links);
+       return cgrp->populated_cnt;
 }
 
 /* returns ino associated with a cgroup */
@@ -490,6 +516,19 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
        pr_cont_kernfs_path(cgrp->kn);
 }
 
+/**
+ * cgroup_file_notify - generate a file modified event for a cgroup_file
+ * @cfile: target cgroup_file
+ *
+ * @cfile must have been obtained by setting cftype->file_offset.
+ */
+static inline void cgroup_file_notify(struct cgroup_file *cfile)
+{
+       /* might not have been created due to one of the CFTYPE selector flags */
+       if (cfile->kn)
+               kernfs_notify(cfile->kn);
+}
+
 #else /* !CONFIG_CGROUPS */
 
 struct cgroup_subsys_state;
@@ -509,6 +548,7 @@ static inline void cgroup_cancel_fork(struct task_struct *p,
 static inline void cgroup_post_fork(struct task_struct *p,
                                    void *ss_priv[CGROUP_CANFORK_COUNT]) {}
 static inline void cgroup_exit(struct task_struct *p) {}
+static inline void cgroup_free(struct task_struct *p) {}
 
 static inline int cgroup_init_early(void) { return 0; }
 static inline int cgroup_init(void) { return 0; }