[PATCH 3/6] cgroup: clean up cgroup_subsys names and initialization

Tejun Heo
2014-01-17T18:13:24Z

cgroup_subsys is a bit messier than it needs to be.

* The name of a subsys can be different from its internal identifier
defined in cgroup_subsys.h. Most subsystems use the matching name
but three - cpu, memory and perf_event - use different ones.

* cgroup_subsys_id enums are postfixed with _subsys_id and each
cgroup_subsys is postfixed with _subsys. cgroup.h is widely
included throughout various subsystems, it doesn't and shouldn't
have claim on such generic names which don't have any qualifier
indicating that they belong to cgroup.

* cgroup_subsys->subsys_id should always equal the matching
cgroup_subsys_id enum; however, we require each controller to
initialize it and then BUG if they don't match, which is a bit
silly.

This patch cleans up cgroup_subsys names and initialization by doing
the followings.

* cgroup_subsys_id enums are now postfixed with _cgrp_id, and each
cgroup_subsys with _cgrp_subsys.

* With the above, renaming subsys identifiers to match the userland
visible names doesn't cause any naming conflicts. All non-matching
identifiers are renamed to match the official names.

cpu_cgroup -> cpu
mem_cgroup -> memory
perf -> perf_event

* controllers no longer need to initialize ->subsys_id and ->name.
They're generated in cgroup core and set automatically during boot.

* Redundant cgroup_subsys declarations removed.

* While updating BUG_ON()s in cgroup_init_early(), convert them to
WARN()s. BUGging that early during boot is stupid - the kernel
can't print anything, even through serial console and the trap
handler doesn't even link stack frame properly for back-tracing.

This patch doesn't introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: "David S. Miller" <davem@davemloft.net>
---
block/blk-cgroup.c | 8 +++-----
block/blk-cgroup.h | 2 +-
fs/bio.c | 2 +-
include/linux/cgroup.h | 7 ++++---
include/linux/cgroup_subsys.h | 6 +++---
include/linux/hugetlb_cgroup.h | 2 +-
include/linux/memcontrol.h | 2 +-
include/net/cls_cgroup.h | 4 ++--
include/net/netprio_cgroup.h | 4 ++--
kernel/cgroup.c | 34 ++++++++++++++++++++--------------
kernel/cgroup_freezer.c | 8 ++------
kernel/cpuset.c | 10 ++++------
kernel/events/core.c | 8 +++-----
kernel/sched/core.c | 6 ++----
kernel/sched/cpuacct.c | 6 ++----
mm/hugetlb_cgroup.c | 9 +++------
mm/memcontrol.c | 22 ++++++++++------------
net/core/netprio_cgroup.c | 4 +---
net/ipv4/tcp_memcontrol.c | 2 +-
net/sched/cls_cgroup.c | 6 ++----
security/device_cgroup.c | 8 ++------
21 files changed, 70 insertions(+), 90 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 660d419..1cef07c 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -906,16 +906,14 @@ static int blkcg_can_attach(struct cgroup_subsys_state *css,
return ret;
}

-struct cgroup_subsys blkio_subsys = {
- .name = "blkio",
+struct cgroup_subsys blkio_cgrp_subsys = {
.css_alloc = blkcg_css_alloc,
.css_offline = blkcg_css_offline,
.css_free = blkcg_css_free,
.can_attach = blkcg_can_attach,
- .subsys_id = blkio_subsys_id,
.base_cftypes = blkcg_files,
};
-EXPORT_SYMBOL_GPL(blkio_subsys);
+EXPORT_SYMBOL_GPL(blkio_cgrp_subsys);

/**
* blkcg_activate_policy - activate a blkcg policy on a request_queue
@@ -1105,7 +1103,7 @@ int blkcg_policy_register(struct blkcg_policy *pol)

/* everything is in place, add intf files for the new policy */
if (pol->cftypes)
- WARN_ON(cgroup_add_cftypes(&blkio_subsys, pol->cftypes));
+ WARN_ON(cgroup_add_cftypes(&blkio_cgrp_subsys, pol->cftypes));
ret = 0;
out_unlock:
mutex_unlock(&blkcg_pol_mutex);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 1610b22..625d66f 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -186,7 +186,7 @@ static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css)

static inline struct blkcg *task_blkcg(struct task_struct *tsk)
{
- return css_to_blkcg(task_css(tsk, blkio_subsys_id));
+ return css_to_blkcg(task_css(tsk, blkio_cgrp_id));
}

static inline struct blkcg *bio_blkcg(struct bio *bio)
diff --git a/fs/bio.c b/fs/bio.c
index 33d79a4..26a62d7 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -2002,7 +2002,7 @@ int bio_associate_current(struct bio *bio)

/* associate blkcg if exists */
rcu_read_lock();
- css = task_css(current, blkio_subsys_id);
+ css = task_css(current, blkio_cgrp_id);
if (css && css_tryget(css))
bio->bi_css = css;
rcu_read_unlock();
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index d842a73..cd6611e 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -41,7 +41,7 @@ extern int cgroupstats_build(struct cgroupstats *stats,
extern int proc_cgroup_show(struct seq_file *, void *);

/* define the enumeration of all cgroup subsystems */
-#define SUBSYS(_x) _x ## _subsys_id,
+#define SUBSYS(_x) _x ## _cgrp_id,
enum cgroup_subsys_id {
#include <linux/cgroup_subsys.h>
CGROUP_SUBSYS_COUNT,
@@ -573,7 +573,6 @@ struct cgroup_subsys {
struct task_struct *task);
void (*bind)(struct cgroup_subsys_state *root_css);

- int subsys_id;
int disabled;
int early_init;

@@ -592,6 +591,8 @@ struct cgroup_subsys {
bool broken_hierarchy;
bool warned_broken_hierarchy;

+ /* the following two fields are initialized automtically during boot */
+ int subsys_id;
#define MAX_CGROUP_TYPE_NAMELEN 32
const char *name;

@@ -606,7 +607,7 @@ struct cgroup_subsys {
struct cftype_set base_cftset;
};

-#define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys;
+#define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
#include <linux/cgroup_subsys.h>
#undef SUBSYS

diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index cc4cafe..ce9244d 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -12,7 +12,7 @@ SUBSYS(debug)
#endif

#if IS_ENABLED(CONFIG_CGROUP_SCHED)
-SUBSYS(cpu_cgroup)
+SUBSYS(cpu)
#endif

#if IS_ENABLED(CONFIG_CGROUP_CPUACCT)
@@ -20,7 +20,7 @@ SUBSYS(cpuacct)
#endif

#if IS_ENABLED(CONFIG_MEMCG)
-SUBSYS(mem_cgroup)
+SUBSYS(memory)
#endif

#if IS_ENABLED(CONFIG_CGROUP_DEVICE)
@@ -40,7 +40,7 @@ SUBSYS(blkio)
#endif

#if IS_ENABLED(CONFIG_CGROUP_PERF)
-SUBSYS(perf)
+SUBSYS(perf_event)
#endif

#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index ce8217f..e54ba72 100644
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -48,7 +48,7 @@ int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)

static inline bool hugetlb_cgroup_disabled(void)
{
- if (hugetlb_subsys.disabled)
+ if (hugetlb_cgrp_subsys.disabled)
return true;
return false;
}
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b3e7a66..65d4bf4 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -162,7 +162,7 @@ extern int do_swap_account;

static inline bool mem_cgroup_disabled(void)
{
- if (mem_cgroup_subsys.disabled)
+ if (memory_cgrp_subsys.disabled)
return true;
return false;
}
diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index 33d03b6..8807e0e 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h
@@ -35,7 +35,7 @@ static inline u32 task_cls_classid(struct task_struct *p)
return 0;

rcu_read_lock();
- classid = container_of(task_css(p, net_cls_subsys_id),
+ classid = container_of(task_css(p, net_cls_cgrp_id),
struct cgroup_cls_state, css)->classid;
rcu_read_unlock();

@@ -51,7 +51,7 @@ static inline u32 task_cls_classid(struct task_struct *p)
return 0;

rcu_read_lock();
- css = task_css(p, net_cls_subsys_id);
+ css = task_css(p, net_cls_cgrp_id);
if (css)
classid = container_of(css,
struct cgroup_cls_state, css)->classid;
diff --git a/include/net/netprio_cgroup.h b/include/net/netprio_cgroup.h
index 099d027..058ea66 100644
--- a/include/net/netprio_cgroup.h
+++ b/include/net/netprio_cgroup.h
@@ -35,7 +35,7 @@ static inline u32 task_netprioidx(struct task_struct *p)
u32 idx;

rcu_read_lock();
- css = task_css(p, net_prio_subsys_id);
+ css = task_css(p, net_prio_cgrp_id);
idx = css->cgroup->id;
rcu_read_unlock();
return idx;
@@ -49,7 +49,7 @@ static inline u32 task_netprioidx(struct task_struct *p)
u32 idx = 0;

rcu_read_lock();
- css = task_css(p, net_prio_subsys_id);
+ css = task_css(p, net_prio_cgrp_id);
if (css)
idx = css->cgroup->id;
rcu_read_unlock();
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index db97ca9..aace2ee 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -120,10 +120,18 @@ static struct workqueue_struct *cgroup_destroy_wq;
static struct workqueue_struct *cgroup_pidlist_destroy_wq;

/* generate an array of cgroup subsystem pointers */
-#define SUBSYS(_x) [_x ## _subsys_id] = &_x ## _subsys,
+#define SUBSYS(_x) [_x ## _cgrp_id] = &_x ## _cgrp_subsys,
static struct cgroup_subsys *cgroup_subsys[] = {
#include <linux/cgroup_subsys.h>
};
+#undef SUBSYS
+
+/* array of cgroup subsystem names */
+#define SUBSYS(_x) [_x ## _cgrp_id] = #_x,
+static const char *cgroup_subsys_name[] = {
+#include <linux/cgroup_subsys.h>
+};
+#undef SUBSYS

/*
* The dummy hierarchy, reserved for the subsystems that are otherwise
@@ -1066,7 +1074,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
BUG_ON(!mutex_is_locked(&cgroup_mutex));

#ifdef CONFIG_CPUSETS
- mask = ~(1UL << cpuset_subsys_id);
+ mask = ~(1UL << cpuset_cgrp_id);
#endif

memset(opts, 0, sizeof(*opts));
@@ -4524,15 +4532,15 @@ int __init cgroup_init_early(void)
list_add(&init_cgrp_cset_link.cgrp_link, &init_css_set.cgrp_links);

for_each_subsys(ss, i) {
- BUG_ON(!ss->name);
- BUG_ON(strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN);
- BUG_ON(!ss->css_alloc);
- BUG_ON(!ss->css_free);
- if (ss->subsys_id != i) {
- printk(KERN_ERR "cgroup: Subsys %s id == %d\n",
- ss->name, ss->subsys_id);
- BUG();
- }
+ WARN(!ss->css_alloc || !ss->css_free || ss->name || ss->subsys_id,
+ "invalid cgroup_subsys %d:%s css_alloc=%p css_free=%p name:id=%d:%s\n",
+ i, cgroup_subsys_name[i], ss->css_alloc, ss->css_free,
+ ss->subsys_id, ss->name);
+ WARN(strlen(cgroup_subsys_name[i]) > MAX_CGROUP_TYPE_NAMELEN,
+ "cgroup_subsys_name %s too long\n", cgroup_subsys_name[i]);
+
+ ss->subsys_id = i;
+ ss->name = cgroup_subsys_name[i];

if (ss->early_init)
cgroup_init_subsys(ss);
@@ -5162,11 +5170,9 @@ static struct cftype debug_files[] = {
{ } /* terminate */
};

-struct cgroup_subsys debug_subsys = {
- .name = "debug",
+struct cgroup_subsys debug_cgrp_subsys = {
.css_alloc = debug_css_alloc,
.css_free = debug_css_free,
- .subsys_id = debug_subsys_id,
.base_cftypes = debug_files,
};
#endif /* CONFIG_CGROUP_DEBUG */
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 6c3154e..98ea26a9 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -52,7 +52,7 @@ static inline struct freezer *css_freezer(struct cgroup_subsys_state *css)

static inline struct freezer *task_freezer(struct task_struct *task)
{
- return css_freezer(task_css(task, freezer_subsys_id));
+ return css_freezer(task_css(task, freezer_cgrp_id));
}

static struct freezer *parent_freezer(struct freezer *freezer)
@@ -84,8 +84,6 @@ static const char *freezer_state_strs(unsigned int state)
return "THAWED";
};

-struct cgroup_subsys freezer_subsys;
-
static struct cgroup_subsys_state *
freezer_css_alloc(struct cgroup_subsys_state *parent_css)
{
@@ -473,13 +471,11 @@ static struct cftype files[] = {
{ } /* terminate */
};

-struct cgroup_subsys freezer_subsys = {
- .name = "freezer",
+struct cgroup_subsys freezer_cgrp_subsys = {
.css_alloc = freezer_css_alloc,
.css_online = freezer_css_online,
.css_offline = freezer_css_offline,
.css_free = freezer_css_free,
- .subsys_id = freezer_subsys_id,
.attach = freezer_attach,
.fork = freezer_fork,
.base_cftypes = files,
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 4410ac6..2d018c7 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -119,7 +119,7 @@ static inline struct cpuset *css_cs(struct cgroup_subsys_state *css)
/* Retrieve the cpuset for a task */
static inline struct cpuset *task_cs(struct task_struct *task)
{
- return css_cs(task_css(task, cpuset_subsys_id));
+ return css_cs(task_css(task, cpuset_cgrp_id));
}

static inline struct cpuset *parent_cs(struct cpuset *cs)
@@ -1521,7 +1521,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
struct task_struct *task;
struct task_struct *leader = cgroup_taskset_first(tset);
struct cgroup_subsys_state *oldcss = cgroup_taskset_cur_css(tset,
- cpuset_subsys_id);
+ cpuset_cgrp_id);
struct cpuset *cs = css_cs(css);
struct cpuset *oldcs = css_cs(oldcss);
struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
@@ -2024,8 +2024,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
kfree(cs);
}

-struct cgroup_subsys cpuset_subsys = {
- .name = "cpuset",
+struct cgroup_subsys cpuset_cgrp_subsys = {
.css_alloc = cpuset_css_alloc,
.css_online = cpuset_css_online,
.css_offline = cpuset_css_offline,
@@ -2033,7 +2032,6 @@ struct cgroup_subsys cpuset_subsys = {
.can_attach = cpuset_can_attach,
.cancel_attach = cpuset_cancel_attach,
.attach = cpuset_attach,
- .subsys_id = cpuset_subsys_id,
.base_cftypes = files,
.early_init = 1,
};
@@ -2699,7 +2697,7 @@ int proc_cpuset_show(struct seq_file *m, void *unused_v)
goto out_free;

rcu_read_lock();
- css = task_css(tsk, cpuset_subsys_id);
+ css = task_css(tsk, cpuset_cgrp_id);
retval = cgroup_path(css->cgroup, buf, PAGE_SIZE);
rcu_read_unlock();
if (retval < 0)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d724e77..1288aab 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -341,7 +341,7 @@ struct perf_cgroup {
static inline struct perf_cgroup *
perf_cgroup_from_task(struct task_struct *task)
{
- return container_of(task_css(task, perf_subsys_id),
+ return container_of(task_css(task, perf_event_cgrp_id),
struct perf_cgroup, css);
}

@@ -594,7 +594,7 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,

rcu_read_lock();

- css = css_from_dir(f.file->f_dentry, &perf_subsys);
+ css = css_from_dir(f.file->f_dentry, &perf_event_cgrp_subsys);
if (IS_ERR(css)) {
ret = PTR_ERR(css);
goto out;
@@ -8025,9 +8025,7 @@ static void perf_cgroup_exit(struct cgroup_subsys_state *css,
task_function_call(task, __perf_cgroup_move, task);
}

-struct cgroup_subsys perf_subsys = {
- .name = "perf_event",
- .subsys_id = perf_subsys_id,
+struct cgroup_subsys perf_event_cgrp_subsys = {
.css_alloc = perf_cgroup_css_alloc,
.css_free = perf_cgroup_css_free,
.exit = perf_cgroup_exit,
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7e8cbb9..3e9b81f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6604,7 +6604,7 @@ void sched_move_task(struct task_struct *tsk)
if (unlikely(running))
tsk->sched_class->put_prev_task(rq, tsk);

- tg = container_of(task_css_check(tsk, cpu_cgroup_subsys_id,
+ tg = container_of(task_css_check(tsk, cpu_cgrp_id,
lockdep_is_held(&tsk->sighand->siglock)),
struct task_group, css);
tg = autogroup_task_group(tsk, tg);
@@ -7335,8 +7335,7 @@ static struct cftype cpu_files[] = {
{ } /* terminate */
};

-struct cgroup_subsys cpu_cgroup_subsys = {
- .name = "cpu",
+struct cgroup_subsys cpu_cgrp_subsys = {
.css_alloc = cpu_cgroup_css_alloc,
.css_free = cpu_cgroup_css_free,
.css_online = cpu_cgroup_css_online,
@@ -7344,7 +7343,6 @@ struct cgroup_subsys cpu_cgroup_subsys = {
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
.exit = cpu_cgroup_exit,
- .subsys_id = cpu_cgroup_subsys_id,
.base_cftypes = cpu_files,
.early_init = 1,
};
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 622e081..c143ee3 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -41,7 +41,7 @@ static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
/* return cpu accounting group to which this task belongs */
static inline struct cpuacct *task_ca(struct task_struct *tsk)
{
- return css_ca(task_css(tsk, cpuacct_subsys_id));
+ return css_ca(task_css(tsk, cpuacct_cgrp_id));
}

static inline struct cpuacct *parent_ca(struct cpuacct *ca)
@@ -275,11 +275,9 @@ void cpuacct_account_field(struct task_struct *p, int index, u64 val)
rcu_read_unlock();
}

-struct cgroup_subsys cpuacct_subsys = {
- .name = "cpuacct",
+struct cgroup_subsys cpuacct_cgrp_subsys = {
.css_alloc = cpuacct_css_alloc,
.css_free = cpuacct_css_free,
- .subsys_id = cpuacct_subsys_id,
.base_cftypes = files,
.early_init = 1,
};
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index d747a84..33a430c 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -30,7 +30,6 @@ struct hugetlb_cgroup {
#define MEMFILE_IDX(val) (((val) >> 16) & 0xffff)
#define MEMFILE_ATTR(val) ((val) & 0xffff)

-struct cgroup_subsys hugetlb_subsys __read_mostly;
static struct hugetlb_cgroup *root_h_cgroup __read_mostly;

static inline
@@ -42,7 +41,7 @@ struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
static inline
struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task)
{
- return hugetlb_cgroup_from_css(task_css(task, hugetlb_subsys_id));
+ return hugetlb_cgroup_from_css(task_css(task, hugetlb_cgrp_id));
}

static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
@@ -358,7 +357,7 @@ static void __init __hugetlb_cgroup_file_init(int idx)
cft = &h->cgroup_files[4];
memset(cft, 0, sizeof(*cft));

- WARN_ON(cgroup_add_cftypes(&hugetlb_subsys, h->cgroup_files));
+ WARN_ON(cgroup_add_cftypes(&hugetlb_cgrp_subsys, h->cgroup_files));

return;
}
@@ -402,10 +401,8 @@ void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
return;
}

-struct cgroup_subsys hugetlb_subsys = {
- .name = "hugetlb",
+struct cgroup_subsys hugetlb_cgrp_subsys = {
.css_alloc = hugetlb_cgroup_css_alloc,
.css_offline = hugetlb_cgroup_css_offline,
.css_free = hugetlb_cgroup_css_free,
- .subsys_id = hugetlb_subsys_id,
};
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9252219..0adfdb1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -67,8 +67,8 @@

#include <trace/events/vmscan.h>

-struct cgroup_subsys mem_cgroup_subsys __read_mostly;
-EXPORT_SYMBOL(mem_cgroup_subsys);
+struct cgroup_subsys memory_cgrp_subsys __read_mostly;
+EXPORT_SYMBOL(memory_cgrp_subsys);

#define MEM_CGROUP_RECLAIM_RETRIES 5
static struct mem_cgroup *root_mem_cgroup __read_mostly;
@@ -560,7 +560,7 @@ static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
{
struct cgroup_subsys_state *css;

- css = css_from_id(id - 1, &mem_cgroup_subsys);
+ css = css_from_id(id - 1, &memory_cgrp_subsys);
return mem_cgroup_from_css(css);
}

@@ -1094,7 +1094,7 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
if (unlikely(!p))
return NULL;

- return mem_cgroup_from_css(task_css(p, mem_cgroup_subsys_id));
+ return mem_cgroup_from_css(task_css(p, memory_cgrp_id));
}

struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
@@ -1706,7 +1706,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
rcu_read_lock();

mem_cgrp = memcg->css.cgroup;
- task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
+ task_cgrp = task_cgroup(p, memory_cgrp_id);

ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
if (ret < 0) {
@@ -6187,7 +6187,7 @@ static int memcg_write_event_control(struct cgroup_subsys_state *css,

ret = -EINVAL;
cfile_css = css_from_dir(cfile.file->f_dentry->d_parent,
- &mem_cgroup_subsys);
+ &memory_cgrp_subsys);
if (cfile_css == css && css_tryget(css))
ret = 0;

@@ -6576,10 +6576,10 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
* unfortunate state in our controller.
*/
if (parent != root_mem_cgroup)
- mem_cgroup_subsys.broken_hierarchy = true;
+ memory_cgrp_subsys.broken_hierarchy = true;
}

- error = memcg_init_kmem(memcg, &mem_cgroup_subsys);
+ error = memcg_init_kmem(memcg, &memory_cgrp_subsys);
mutex_unlock(&memcg_create_mutex);
return error;
}
@@ -7239,9 +7239,7 @@ static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
mem_cgroup_from_css(root_css)->use_hierarchy = true;
}

-struct cgroup_subsys mem_cgroup_subsys = {
- .name = "memory",
- .subsys_id = mem_cgroup_subsys_id,
+struct cgroup_subsys memory_cgrp_subsys = {
.css_alloc = mem_cgroup_css_alloc,
.css_online = mem_cgroup_css_online,
.css_offline = mem_cgroup_css_offline,
@@ -7267,7 +7265,7 @@ __setup("swapaccount=", enable_swap_account);

static void __init memsw_file_init(void)
{
- WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files));
+ WARN_ON(cgroup_add_cftypes(&memory_cgrp_subsys, memsw_cgroup_files));
}

static void __init enable_swap_cgroup(void)
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index a34df14..ece50fc 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -244,13 +244,11 @@ static struct cftype ss_files[] = {
{ } /* terminate */
};

-struct cgroup_subsys net_prio_subsys = {
- .name = "net_prio",
+struct cgroup_subsys net_prio_cgrp_subsys = {
.css_alloc = cgrp_css_alloc,
.css_online = cgrp_css_online,
.css_free = cgrp_css_free,
.attach = net_prio_attach,
- .subsys_id = net_prio_subsys_id,
.base_cftypes = ss_files,
};

diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
index 03e9154..d441c1a 100644
--- a/net/ipv4/tcp_memcontrol.c
+++ b/net/ipv4/tcp_memcontrol.c
@@ -228,7 +228,7 @@ static struct cftype tcp_files[] = {

static int __init tcp_memcontrol_init(void)
{
- WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, tcp_files));
+ WARN_ON(cgroup_add_cftypes(&memory_cgrp_subsys, tcp_files));
return 0;
}
__initcall(tcp_memcontrol_init);
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 706ec7b..89ce1df 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -30,7 +30,7 @@ static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state

static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
{
- return css_cls_state(task_css(p, net_cls_subsys_id));
+ return css_cls_state(task_css(p, net_cls_cgrp_id));
}

static struct cgroup_subsys_state *
@@ -103,13 +103,11 @@ static struct cftype ss_files[] = {
{ } /* terminate */
};

-struct cgroup_subsys net_cls_subsys = {
- .name = "net_cls",
+struct cgroup_subsys net_cls_cgrp_subsys = {
.css_alloc = cgrp_css_alloc,
.css_online = cgrp_css_online,
.css_free = cgrp_css_free,
.attach = cgrp_attach,
- .subsys_id = net_cls_subsys_id,
.base_cftypes = ss_files,
};

diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index d3b6d2c..7f88bcd 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -58,11 +58,9 @@ static inline struct dev_cgroup *css_to_devcgroup(struct cgroup_subsys_state *s)

static inline struct dev_cgroup *task_devcgroup(struct task_struct *task)
{
- return css_to_devcgroup(task_css(task, devices_subsys_id));
+ return css_to_devcgroup(task_css(task, devices_cgrp_id));
}

-struct cgroup_subsys devices_subsys;
-
/*
* called under devcgroup_mutex
*/
@@ -684,13 +682,11 @@ static struct cftype dev_cgroup_files[] = {
{ } /* terminate */
};

-struct cgroup_subsys devices_subsys = {
- .name = "devices",
+struct cgroup_subsys devices_cgrp_subsys = {
.css_alloc = devcgroup_css_alloc,
.css_free = devcgroup_css_free,
.css_online = devcgroup_online,
.css_offline = devcgroup_offline,
- .subsys_id = devices_subsys_id,
.base_cftypes = dev_cgroup_files,
};

--
1.8.4.2