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-rw-r--r--Documentation/cgroups.txt22
1 files changed, 11 insertions, 11 deletions
diff --git a/Documentation/cgroups.txt b/Documentation/cgroups.txt
index 98a26f81fa7..42d7c4cb39c 100644
--- a/Documentation/cgroups.txt
+++ b/Documentation/cgroups.txt
@@ -456,7 +456,7 @@ methods are create/destroy. Any others that are null are presumed to
be successful no-ops.
struct cgroup_subsys_state *create(struct cgroup *cont)
-LL=cgroup_mutex
+(cgroup_mutex held by caller)
Called to create a subsystem state object for a cgroup. The
subsystem should allocate its subsystem state object for the passed
@@ -471,14 +471,19 @@ it's the root of the hierarchy) and may be an appropriate place for
initialization code.
void destroy(struct cgroup *cont)
-LL=cgroup_mutex
+(cgroup_mutex held by caller)
-The cgroup system is about to destroy the passed cgroup; the
-subsystem should do any necessary cleanup
+The cgroup system is about to destroy the passed cgroup; the subsystem
+should do any necessary cleanup and free its subsystem state
+object. By the time this method is called, the cgroup has already been
+unlinked from the file system and from the child list of its parent;
+cgroup->parent is still valid. (Note - can also be called for a
+newly-created cgroup if an error occurs after this subsystem's
+create() method has been called for the new cgroup).
int can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
struct task_struct *task)
-LL=cgroup_mutex
+(cgroup_mutex held by caller)
Called prior to moving a task into a cgroup; if the subsystem
returns an error, this will abort the attach operation. If a NULL
@@ -489,25 +494,20 @@ remain valid while the caller holds cgroup_mutex.
void attach(struct cgroup_subsys *ss, struct cgroup *cont,
struct cgroup *old_cont, struct task_struct *task)
-LL=cgroup_mutex
-
Called after the task has been attached to the cgroup, to allow any
post-attachment activity that requires memory allocations or blocking.
void fork(struct cgroup_subsy *ss, struct task_struct *task)
-LL=callback_mutex, maybe read_lock(tasklist_lock)
Called when a task is forked into a cgroup. Also called during
registration for all existing tasks.
void exit(struct cgroup_subsys *ss, struct task_struct *task)
-LL=callback_mutex
Called during task exit
int populate(struct cgroup_subsys *ss, struct cgroup *cont)
-LL=none
Called after creation of a cgroup to allow a subsystem to populate
the cgroup directory with file entries. The subsystem should make
@@ -524,7 +524,7 @@ example in cpusets, no task may attach before 'cpus' and 'mems' are set
up.
void bind(struct cgroup_subsys *ss, struct cgroup *root)
-LL=callback_mutex
+(cgroup_mutex held by caller)
Called when a cgroup subsystem is rebound to a different hierarchy
and root cgroup. Currently this will only involve movement between