memcg: rename cgroup_event to mem_cgroup_event (3bc942f3) · Commits · 戴 / test

Documentation/cgroups/cgroups.txt

+0 −20

Original line number	Diff line number	Diff line
		@@ -24,7 +24,6 @@ CONTENTS:
		2.1 Basic Usage
		2.2 Attaching processes
		2.3 Mounting hierarchies by name
		2.4 Notification API
		3. Kernel API
		3.1 Overview
		3.2 Synchronization
		@@ -472,25 +471,6 @@ you give a subsystem a name.
		The name of the subsystem appears as part of the hierarchy description
		in /proc/mounts and /proc/<pid>/cgroups.

		2.4 Notification API
		--------------------

		There is mechanism which allows to get notifications about changing
		status of a cgroup.

		To register a new notification handler you need to:
		- create a file descriptor for event notification using eventfd(2);
		- open a control file to be monitored (e.g. memory.usage_in_bytes);
		- write "<event_fd> <control_fd> <args>" to cgroup.event_control.
		Interpretation of args is defined by control file implementation;

		eventfd will be woken up by control file implementation or when the
		cgroup is removed.

		To unregister a notification handler just close eventfd.

		NOTE: Support of notifications should be implemented for the control
		file. See documentation for the subsystem.

		3. Kernel API
		=============

mm/memcontrol.c

+37 −20

Original line number	Diff line number	Diff line
		@@ -231,7 +231,7 @@ struct mem_cgroup_eventfd_list {
		/*
		* cgroup_event represents events which userspace want to receive.
		*/
		struct cgroup_event {
		struct mem_cgroup_event {
		/*
		* memcg which the event belongs to.
		*/
		@@ -6001,15 +6001,28 @@ static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
		}
		#endif

		/*
		* DO NOT USE IN NEW FILES.
		*
		* "cgroup.event_control" implementation.
		*
		* This is way over-engineered. It tries to support fully configurable
		* events for each user. Such level of flexibility is completely
		* unnecessary especially in the light of the planned unified hierarchy.
		*
		* Please deprecate this and replace with something simpler if at all
		* possible.
		*/

		/*
		* Unregister event and free resources.
		*
		* Gets called from workqueue.
		*/
		static void cgroup_event_remove(struct work_struct *work)
		static void memcg_event_remove(struct work_struct *work)
		{
		struct cgroup_event *event = container_of(work, struct cgroup_event,
		remove);
		struct mem_cgroup_event *event =
		container_of(work, struct mem_cgroup_event, remove);
		struct mem_cgroup *memcg = event->memcg;

		remove_wait_queue(event->wqh, &event->wait);
		@@ -6029,11 +6042,11 @@ static void cgroup_event_remove(struct work_struct *work)
		*
		* Called with wqh->lock held and interrupts disabled.
		*/
		static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
		static int memcg_event_wake(wait_queue_t *wait, unsigned mode,
		int sync, void *key)
		{
		struct cgroup_event *event = container_of(wait,
		struct cgroup_event, wait);
		struct mem_cgroup_event *event =
		container_of(wait, struct mem_cgroup_event, wait);
		struct mem_cgroup *memcg = event->memcg;
		unsigned long flags = (unsigned long)key;

		@@ -6062,27 +6075,29 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
		return 0;
		}

		static void cgroup_event_ptable_queue_proc(struct file *file,
		static void memcg_event_ptable_queue_proc(struct file *file,
		wait_queue_head_t wqh, poll_table pt)
		{
		struct cgroup_event *event = container_of(pt,
		struct cgroup_event, pt);
		struct mem_cgroup_event *event =
		container_of(pt, struct mem_cgroup_event, pt);

		event->wqh = wqh;
		add_wait_queue(wqh, &event->wait);
		}

		/*
		* DO NOT USE IN NEW FILES.
		*
		* Parse input and register new cgroup event handler.
		*
		* Input must be in format '<event_fd> <control_fd> <args>'.
		* Interpretation of args is defined by control file implementation.
		*/
		static int cgroup_write_event_control(struct cgroup_subsys_state *css,
		static int memcg_write_event_control(struct cgroup_subsys_state *css,
		struct cftype cft, const char buffer)
		{
		struct mem_cgroup *memcg = mem_cgroup_from_css(css);
		struct cgroup_event *event;
		struct mem_cgroup_event *event;
		struct cgroup_subsys_state *cfile_css;
		unsigned int efd, cfd;
		struct fd efile;
		@@ -6107,9 +6122,9 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *css,

		event->memcg = memcg;
		INIT_LIST_HEAD(&event->list);
		init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc);
		init_waitqueue_func_entry(&event->wait, cgroup_event_wake);
		INIT_WORK(&event->remove, cgroup_event_remove);
		init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
		init_waitqueue_func_entry(&event->wait, memcg_event_wake);
		INIT_WORK(&event->remove, memcg_event_remove);

		efile = fdget(efd);
		if (!efile.file) {
		@@ -6140,6 +6155,8 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *css,
		* to be done via struct cftype but cgroup core no longer knows
		* about these events. The following is crude but the whole thing
		* is for compatibility anyway.
		*
		* DO NOT ADD NEW FILES.
		*/
		name = cfile.file->f_dentry->d_name.name;

		@@ -6251,8 +6268,8 @@ static struct cftype mem_cgroup_files[] = {
		.read_u64 = mem_cgroup_hierarchy_read,
		},
		{
		.name = "cgroup.event_control",
		.write_string = cgroup_write_event_control,
		.name = "cgroup.event_control", /* XXX: for compat */
		.write_string = memcg_write_event_control,
		.flags = CFTYPE_NO_PREFIX,
		.mode = S_IWUGO,
		},
		@@ -6585,7 +6602,7 @@ static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
		static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
		{
		struct mem_cgroup *memcg = mem_cgroup_from_css(css);
		struct cgroup_event event, tmp;
		struct mem_cgroup_event event, tmp;

		/*
		* Unregister events and notify userspace.

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