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authorTejun Heo <tj@kernel.org>2013-11-22 18:20:43 -0500
committerTejun Heo <tj@kernel.org>2013-11-22 18:20:43 -0500
commitfba94807837850e211f8975e1970e23e7804ff4d (patch)
treec26b1b43027424574532e3fa74ed4656e445334a
parentb5557c4c3b1a38074d7001b87c2482eda3a0834a (diff)
cgroup, memcg: move cgroup->event_list[_lock] and event callbacks into memcg
cgroup_event is being moved from cgroup core to memcg and the implementation is already moved by the previous patch. This patch moves the data fields and callbacks. * cgroup->event_list[_lock] are moved to mem_cgroup. * cftype->[un]register_event() are moved to cgroup_event. This makes it impossible for individual cftype definitions to specify their event callbacks. This is worked around by simply hard-coding filename to event callback mapping in cgroup_write_event_control(). This is awkward and inflexible, which is actually desirable given that we don't want to grow more usages of this feature. * eventfd_ctx declaration is removed from cgroup.h, which makes vmpressure.h miss eventfd_ctx declaration. Include eventfd.h from vmpressure.h. v2: Use file name from dentry instead of cftype. This will allow removing all cftype handling in the function. 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> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com>
-rw-r--r--include/linux/cgroup.h24
-rw-r--r--include/linux/vmpressure.h1
-rw-r--r--kernel/cgroup.c2
-rw-r--r--mm/memcontrol.c87
4 files changed, 61 insertions, 53 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 40c2427806c9..612adc5b87c5 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -29,7 +29,6 @@ struct cgroup_subsys;
struct inode;
struct cgroup;
struct css_id;
-struct eventfd_ctx;
extern int cgroup_init_early(void);
extern int cgroup_init(void);
@@ -239,10 +238,6 @@ struct cgroup {
struct rcu_head rcu_head;
struct work_struct destroy_work;
- /* List of events which userspace want to receive */
- struct list_head event_list;
- spinlock_t event_list_lock;
-
/* directory xattrs */
struct simple_xattrs xattrs;
};
@@ -506,25 +501,6 @@ struct cftype {
int (*trigger)(struct cgroup_subsys_state *css, unsigned int event);
int (*release)(struct inode *inode, struct file *file);
-
- /*
- * register_event() callback will be used to add new userspace
- * waiter for changes related to the cftype. Implement it if
- * you want to provide this functionality. Use eventfd_signal()
- * on eventfd to send notification to userspace.
- */
- int (*register_event)(struct cgroup_subsys_state *css,
- struct cftype *cft, struct eventfd_ctx *eventfd,
- const char *args);
- /*
- * unregister_event() callback will be called when userspace
- * closes the eventfd or on cgroup removing.
- * This callback must be implemented, if you want provide
- * notification functionality.
- */
- void (*unregister_event)(struct cgroup_subsys_state *css,
- struct cftype *cft,
- struct eventfd_ctx *eventfd);
};
/*
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
index 3f3788d49362..9dd1914f1a6c 100644
--- a/include/linux/vmpressure.h
+++ b/include/linux/vmpressure.h
@@ -7,6 +7,7 @@
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/cgroup.h>
+#include <linux/eventfd.h>
struct vmpressure {
unsigned long scanned;
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 4bccaa7dda35..feda7c54fa6b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1352,8 +1352,6 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
INIT_LIST_HEAD(&cgrp->pidlists);
mutex_init(&cgrp->pidlist_mutex);
cgrp->dummy_css.cgroup = cgrp;
- INIT_LIST_HEAD(&cgrp->event_list);
- spin_lock_init(&cgrp->event_list_lock);
simple_xattrs_init(&cgrp->xattrs);
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d00368110b08..2fcacb18404b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -249,6 +249,22 @@ struct cgroup_event {
*/
struct list_head list;
/*
+ * register_event() callback will be used to add new userspace
+ * waiter for changes related to this event. Use eventfd_signal()
+ * on eventfd to send notification to userspace.
+ */
+ int (*register_event)(struct cgroup_subsys_state *css,
+ struct cftype *cft, struct eventfd_ctx *eventfd,
+ const char *args);
+ /*
+ * unregister_event() callback will be called when userspace closes
+ * the eventfd or on cgroup removing. This callback must be set,
+ * if you want provide notification functionality.
+ */
+ void (*unregister_event)(struct cgroup_subsys_state *css,
+ struct cftype *cft,
+ struct eventfd_ctx *eventfd);
+ /*
* All fields below needed to unregister event when
* userspace closes eventfd.
*/
@@ -362,6 +378,10 @@ struct mem_cgroup {
atomic_t numainfo_updating;
#endif
+ /* List of events which userspace want to receive */
+ struct list_head event_list;
+ spinlock_t event_list_lock;
+
struct mem_cgroup_per_node *nodeinfo[0];
/* WARNING: nodeinfo must be the last member here */
};
@@ -5992,7 +6012,7 @@ static void cgroup_event_remove(struct work_struct *work)
remove_wait_queue(event->wqh, &event->wait);
- event->cft->unregister_event(css, event->cft, event->eventfd);
+ event->unregister_event(css, event->cft, event->eventfd);
/* Notify userspace the event is going away. */
eventfd_signal(event->eventfd, 1);
@@ -6012,7 +6032,7 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
{
struct cgroup_event *event = container_of(wait,
struct cgroup_event, wait);
- struct cgroup *cgrp = event->css->cgroup;
+ struct mem_cgroup *memcg = mem_cgroup_from_css(event->css);
unsigned long flags = (unsigned long)key;
if (flags & POLLHUP) {
@@ -6025,7 +6045,7 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
* side will require wqh->lock via remove_wait_queue(),
* which we hold.
*/
- spin_lock(&cgrp->event_list_lock);
+ spin_lock(&memcg->event_list_lock);
if (!list_empty(&event->list)) {
list_del_init(&event->list);
/*
@@ -6034,7 +6054,7 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
*/
schedule_work(&event->remove);
}
- spin_unlock(&cgrp->event_list_lock);
+ spin_unlock(&memcg->event_list_lock);
}
return 0;
@@ -6059,12 +6079,13 @@ static void cgroup_event_ptable_queue_proc(struct file *file,
static int cgroup_write_event_control(struct cgroup_subsys_state *css,
struct cftype *cft, const char *buffer)
{
- struct cgroup *cgrp = css->cgroup;
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct cgroup_event *event;
struct cgroup_subsys_state *cfile_css;
unsigned int efd, cfd;
struct fd efile;
struct fd cfile;
+ const char *name;
char *endp;
int ret;
@@ -6119,6 +6140,31 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *css,
}
/*
+ * Determine the event callbacks and set them in @event. This used
+ * 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.
+ */
+ name = cfile.file->f_dentry->d_name.name;
+
+ if (!strcmp(name, "memory.usage_in_bytes")) {
+ event->register_event = mem_cgroup_usage_register_event;
+ event->unregister_event = mem_cgroup_usage_unregister_event;
+ } else if (!strcmp(name, "memory.oom_control")) {
+ event->register_event = mem_cgroup_oom_register_event;
+ event->unregister_event = mem_cgroup_oom_unregister_event;
+ } else if (!strcmp(name, "memory.pressure_level")) {
+ event->register_event = vmpressure_register_event;
+ event->unregister_event = vmpressure_unregister_event;
+ } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
+ event->register_event = mem_cgroup_usage_register_event;
+ event->unregister_event = mem_cgroup_usage_unregister_event;
+ } else {
+ ret = -EINVAL;
+ goto out_put_cfile;
+ }
+
+ /*
* Verify @cfile should belong to @css. Also, remaining events are
* automatically removed on cgroup destruction but the removal is
* asynchronous, so take an extra ref on @css.
@@ -6135,21 +6181,15 @@ static int cgroup_write_event_control(struct cgroup_subsys_state *css,
if (ret)
goto out_put_cfile;
- if (!event->cft->register_event || !event->cft->unregister_event) {
- ret = -EINVAL;
- goto out_put_css;
- }
-
- ret = event->cft->register_event(css, event->cft,
- event->eventfd, buffer);
+ ret = event->register_event(css, event->cft, event->eventfd, buffer);
if (ret)
goto out_put_css;
efile.file->f_op->poll(efile.file, &event->pt);
- spin_lock(&cgrp->event_list_lock);
- list_add(&event->list, &cgrp->event_list);
- spin_unlock(&cgrp->event_list_lock);
+ spin_lock(&memcg->event_list_lock);
+ list_add(&event->list, &memcg->event_list);
+ spin_unlock(&memcg->event_list_lock);
fdput(cfile);
fdput(efile);
@@ -6175,8 +6215,6 @@ static struct cftype mem_cgroup_files[] = {
.name = "usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
.read = mem_cgroup_read,
- .register_event = mem_cgroup_usage_register_event,
- .unregister_event = mem_cgroup_usage_unregister_event,
},
{
.name = "max_usage_in_bytes",
@@ -6236,14 +6274,10 @@ static struct cftype mem_cgroup_files[] = {
.name = "oom_control",
.read_map = mem_cgroup_oom_control_read,
.write_u64 = mem_cgroup_oom_control_write,
- .register_event = mem_cgroup_oom_register_event,
- .unregister_event = mem_cgroup_oom_unregister_event,
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
},
{
.name = "pressure_level",
- .register_event = vmpressure_register_event,
- .unregister_event = vmpressure_unregister_event,
},
#ifdef CONFIG_NUMA
{
@@ -6291,8 +6325,6 @@ static struct cftype memsw_cgroup_files[] = {
.name = "memsw.usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
.read = mem_cgroup_read,
- .register_event = mem_cgroup_usage_register_event,
- .unregister_event = mem_cgroup_usage_unregister_event,
},
{
.name = "memsw.max_usage_in_bytes",
@@ -6483,6 +6515,8 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
mutex_init(&memcg->thresholds_lock);
spin_lock_init(&memcg->move_lock);
vmpressure_init(&memcg->vmpressure);
+ INIT_LIST_HEAD(&memcg->event_list);
+ spin_lock_init(&memcg->event_list_lock);
return &memcg->css;
@@ -6555,7 +6589,6 @@ 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 *cgrp = css->cgroup;
struct cgroup_event *event, *tmp;
/*
@@ -6563,12 +6596,12 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
* Notify userspace about cgroup removing only after rmdir of cgroup
* directory to avoid race between userspace and kernelspace.
*/
- spin_lock(&cgrp->event_list_lock);
- list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) {
+ spin_lock(&memcg->event_list_lock);
+ list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
list_del_init(&event->list);
schedule_work(&event->remove);
}
- spin_unlock(&cgrp->event_list_lock);
+ spin_unlock(&memcg->event_list_lock);
kmem_cgroup_css_offline(memcg);