memcg: rename cgroup_event to mem_cgroup_event
cgroup_event is only available in memcg now. Let's brand it that way.
While at it, add a comment encouraging deprecation of the feature and
remove the respective section from cgroup documentation.
This patch is cosmetic.
v3: Typo update as per Li Zefan.
v2: Index in cgroups.txt updated accordingly as suggested by Li Zefan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 42f2843..ec8582b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -231,7 +231,7 @@
/*
* cgroup_event represents events which userspace want to receive.
*/
-struct cgroup_event {
+struct mem_cgroup_event {
/*
* memcg which the event belongs to.
*/
@@ -6002,14 +6002,27 @@
#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 @@
*
* Called with wqh->lock held and interrupts disabled.
*/
-static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
- int sync, void *key)
+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 @@
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,
- struct cftype *cft, const char *buffer)
+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 @@
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 @@
* 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 @@
.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_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.