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Date: Fri, 24 Aug 2012 16:01:40 +0200
From: Daniel Wagner <wagi@...om.org>
To: netdev@...r.kernel.org, cgroups@...r.kernel.org
Cc: Daniel Wagner <daniel.wagner@...-carit.de>,
"David S. Miller" <davem@...emloft.net>,
Andrew Morton <akpm@...ux-foundation.org>,
Eric Dumazet <edumazet@...gle.com>,
Gao feng <gaofeng@...fujitsu.com>,
Glauber Costa <glommer@...allels.com>,
Jamal Hadi Salim <jhs@...atatu.com>,
John Fastabend <john.r.fastabend@...el.com>,
Kamezawa Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
Li Zefan <lizefan@...wei.com>,
Neil Horman <nhorman@...driver.com>, Tejun Heo <tj@...nel.org>
Subject: [PATCH v2 06/10] cgroup: Assign subsystem IDs during compile time
From: Daniel Wagner <daniel.wagner@...-carit.de>
We are able to safe some space when we assign the subsystem
IDs at compile time. Instead of allocating per cgroup
cgroup->subsys[CGROUP_SUBSYS_COUNT] where CGROUP_SUBSYS_COUNT is
always 64, we allocate at max 12 (at this point there are 12
subsystem).
task_cls_classid() and task_netprioidx() (when built as
module) are protected by a jump label and therefore we can
simply replace the subsystem index lookup with the enum.
Signed-off-by: Daniel Wagner <daniel.wagner@...-carit.de>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Eric Dumazet <edumazet@...gle.com>
Cc: Gao feng <gaofeng@...fujitsu.com>
Cc: Glauber Costa <glommer@...allels.com>
Cc: Jamal Hadi Salim <jhs@...atatu.com>
Cc: John Fastabend <john.r.fastabend@...el.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Cc: Li Zefan <lizefan@...wei.com>
Cc: Neil Horman <nhorman@...driver.com>
Cc: Tejun Heo <tj@...nel.org>
Cc: netdev@...r.kernel.org
Cc: cgroups@...r.kernel.org
---
include/linux/cgroup.h | 29 ++++++++++++++++++++---------
include/linux/cgroup_subsys.h | 24 ++++++++++++------------
include/net/cls_cgroup.h | 12 +++---------
include/net/netprio_cgroup.h | 17 ++++-------------
kernel/cgroup.c | 25 ++++++-------------------
net/core/netprio_cgroup.c | 11 -----------
net/core/sock.c | 9 ---------
net/sched/cls_cgroup.c | 13 -------------
8 files changed, 45 insertions(+), 95 deletions(-)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 3787872..ada517f 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -43,18 +43,27 @@ extern void cgroup_unload_subsys(struct cgroup_subsys *ss);
extern const struct file_operations proc_cgroup_operations;
-/* Define the enumeration of all builtin cgroup subsystems */
-#define SUBSYS(_x) _x ## _subsys_id,
+/*
+ * Define the enumeration of all builtin cgroup subsystems.
+ * For the builtin subsystems the subsys_id needs to be indentical
+ * with the index in css->subsys. Therefore, all the builtin
+ * subsys are listed first and then the modules ids.
+ */
enum cgroup_subsys_id {
+#define SUBSYS(_x) _x ## _subsys_id,
+
+#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option)
#include <linux/cgroup_subsys.h>
-};
+#undef IS_SUBSYS_ENABLED
+
+#define IS_SUBSYS_ENABLED(option) IS_MODULE(option)
+#include <linux/cgroup_subsys.h>
+#undef IS_SUBSYS_ENABLED
+
#undef SUBSYS
-/*
- * This define indicates the maximum number of subsystems that can be loaded
- * at once. We limit to this many since cgroupfs_root has subsys_bits to keep
- * track of all of them.
- */
-#define CGROUP_SUBSYS_COUNT (BITS_PER_BYTE*sizeof(unsigned long))
+
+ CGROUP_SUBSYS_COUNT,
+};
/* Per-subsystem/per-cgroup state maintained by the system. */
struct cgroup_subsys_state {
@@ -520,8 +529,10 @@ struct cgroup_subsys {
};
#define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys;
+#define IS_SUBSYS_ENABLED(option) IS_ENABLED(option)
#include <linux/cgroup_subsys.h>
#undef SUBSYS
+#undef IS_SUBSYS_ENABLED
static inline struct cgroup_subsys_state *cgroup_subsys_state(
struct cgroup *cgrp, int subsys_id)
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index dfae957..f204a7a 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -7,73 +7,73 @@
/* */
-#ifdef CONFIG_CPUSETS
+#if IS_SUBSYS_ENABLED(CONFIG_CPUSETS)
SUBSYS(cpuset)
#endif
/* */
-#ifdef CONFIG_CGROUP_DEBUG
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_DEBUG)
SUBSYS(debug)
#endif
/* */
-#ifdef CONFIG_CGROUP_SCHED
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_SCHED)
SUBSYS(cpu_cgroup)
#endif
/* */
-#ifdef CONFIG_CGROUP_CPUACCT
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_CPUACCT)
SUBSYS(cpuacct)
#endif
/* */
-#ifdef CONFIG_MEMCG
+#if IS_SUBSYS_ENABLED(CONFIG_MEMCG)
SUBSYS(mem_cgroup)
#endif
/* */
-#ifdef CONFIG_CGROUP_DEVICE
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_DEVICE)
SUBSYS(devices)
#endif
/* */
-#ifdef CONFIG_CGROUP_FREEZER
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_FREEZER)
SUBSYS(freezer)
#endif
/* */
-#ifdef CONFIG_NET_CLS_CGROUP
+#if IS_SUBSYS_ENABLED(CONFIG_NET_CLS_CGROUP)
SUBSYS(net_cls)
#endif
/* */
-#ifdef CONFIG_BLK_CGROUP
+#if IS_SUBSYS_ENABLED(CONFIG_BLK_CGROUP)
SUBSYS(blkio)
#endif
/* */
-#ifdef CONFIG_CGROUP_PERF
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_PERF)
SUBSYS(perf)
#endif
/* */
-#ifdef CONFIG_NETPRIO_CGROUP
+#if IS_SUBSYS_ENABLED(CONFIG_NETPRIO_CGROUP)
SUBSYS(net_prio)
#endif
/* */
-#ifdef CONFIG_CGROUP_HUGETLB
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_HUGETLB)
SUBSYS(hugetlb)
#endif
diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index 24443d2..43fae13 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h
@@ -49,22 +49,16 @@ static inline u32 task_cls_classid(struct task_struct *p)
extern struct static_key cgroup_cls_enabled;
#define clscg_enabled static_key_false(&cgroup_cls_enabled)
-extern int net_cls_subsys_id;
-
static inline u32 task_cls_classid(struct task_struct *p)
{
- int id;
- u32 classid = 0;
+ u32 classid;
if (!clscg_enabled || in_interrupt())
return 0;
rcu_read_lock();
- id = rcu_dereference_index_check(net_cls_subsys_id,
- rcu_read_lock_held());
- if (id >= 0)
- classid = container_of(task_subsys_state(p, id),
- struct cgroup_cls_state, css)->classid;
+ classid = container_of(task_subsys_state(p, net_cls_subsys_id),
+ struct cgroup_cls_state, css)->classid;
rcu_read_unlock();
return classid;
diff --git a/include/net/netprio_cgroup.h b/include/net/netprio_cgroup.h
index 9ff58e4..66241c6 100644
--- a/include/net/netprio_cgroup.h
+++ b/include/net/netprio_cgroup.h
@@ -31,10 +31,6 @@ struct cgroup_netprio_state {
u32 prioidx;
};
-#ifndef CONFIG_NETPRIO_CGROUP
-extern int net_prio_subsys_id;
-#endif
-
extern void sock_update_netprioidx(struct sock *sk, struct task_struct *task);
#if IS_BUILTIN(CONFIG_NETPRIO_CGROUP)
@@ -60,20 +56,15 @@ extern struct static_key cgroup_netprio_enabled;
static inline u32 task_netprioidx(struct task_struct *p)
{
struct cgroup_netprio_state *state;
- int subsys_id;
- u32 idx = 0;
+ u32 idx;
if (!netpriocg_enabled)
return 0;
rcu_read_lock();
- subsys_id = rcu_dereference_index_check(net_prio_subsys_id,
- rcu_read_lock_held());
- if (subsys_id >= 0) {
- state = container_of(task_subsys_state(p, subsys_id),
- struct cgroup_netprio_state, css);
- idx = state->prioidx;
- }
+ state = container_of(task_subsys_state(p, net_prio_subsys_id),
+ struct cgroup_netprio_state, css);
+ idx = state->prioidx;
rcu_read_unlock();
return idx;
}
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f9433b4..ee55f84 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -93,8 +93,11 @@ static DEFINE_MUTEX(cgroup_root_mutex);
* cgroup_mutex.
*/
#define SUBSYS(_x) &_x ## _subsys,
+#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option)
static struct cgroup_subsys *subsys[CGROUP_SUBSYS_COUNT] = {
#include <linux/cgroup_subsys.h>
+#undef IS_SUBSYS_ENABLED
+#undef SUBSYS
};
#define MAX_CGROUP_ROOT_NAMELEN 64
@@ -4336,24 +4339,8 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
/* init base cftset */
cgroup_init_cftsets(ss);
- /*
- * need to register a subsys id before anything else - for example,
- * init_cgroup_css needs it.
- */
mutex_lock(&cgroup_mutex);
- /* find the first empty slot in the array */
- for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
- if (subsys[i] == NULL)
- break;
- }
- if (i == CGROUP_SUBSYS_COUNT) {
- /* maximum number of subsystems already registered! */
- mutex_unlock(&cgroup_mutex);
- return -EBUSY;
- }
- /* assign ourselves the subsys_id */
- ss->subsys_id = i;
- subsys[i] = ss;
+ subsys[ss->subsys_id] = ss;
/*
* no ss->create seems to need anything important in the ss struct, so
@@ -4362,7 +4349,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
css = ss->create(dummytop);
if (IS_ERR(css)) {
/* failure case - need to deassign the subsys[] slot. */
- subsys[i] = NULL;
+ subsys[ss->subsys_id] = NULL;
mutex_unlock(&cgroup_mutex);
return PTR_ERR(css);
}
@@ -4378,7 +4365,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
if (ret) {
dummytop->subsys[ss->subsys_id] = NULL;
ss->destroy(dummytop);
- subsys[i] = NULL;
+ subsys[ss->subsys_id] = NULL;
mutex_unlock(&cgroup_mutex);
return ret;
}
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 400ab94..a029ffe 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -326,9 +326,7 @@ struct cgroup_subsys net_prio_subsys = {
.create = cgrp_create,
.destroy = cgrp_destroy,
.attach = net_prio_attach,
-#ifdef CONFIG_NETPRIO_CGROUP
.subsys_id = net_prio_subsys_id,
-#endif
.base_cftypes = ss_files,
.module = THIS_MODULE
};
@@ -366,10 +364,6 @@ static int __init init_cgroup_netprio(void)
ret = cgroup_load_subsys(&net_prio_subsys);
if (ret)
goto out;
-#ifndef CONFIG_NETPRIO_CGROUP
- smp_wmb();
- net_prio_subsys_id = net_prio_subsys.subsys_id;
-#endif
#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
static_key_slow_inc(&cgroup_netprio_enabled);
@@ -390,11 +384,6 @@ static void __exit exit_cgroup_netprio(void)
cgroup_unload_subsys(&net_prio_subsys);
-#ifndef CONFIG_NETPRIO_CGROUP
- net_prio_subsys_id = -1;
- synchronize_rcu();
-#endif
-
#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
static_key_slow_dec(&cgroup_netprio_enabled);
rcu_barrier();
diff --git a/net/core/sock.c b/net/core/sock.c
index 1f119d2..aa762d9 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -335,15 +335,6 @@ EXPORT_SYMBOL_GPL(cgroup_cls_enabled);
struct static_key cgroup_netprio_enabled = STATIC_KEY_INIT_FALSE;
EXPORT_SYMBOL_GPL(cgroup_netprio_enabled);
#endif
-
-#if !defined(CONFIG_NET_CLS_CGROUP)
-int net_cls_subsys_id = -1;
-EXPORT_SYMBOL_GPL(net_cls_subsys_id);
-#endif
-#if !defined(CONFIG_NETPRIO_CGROUP)
-int net_prio_subsys_id = -1;
-EXPORT_SYMBOL_GPL(net_prio_subsys_id);
-#endif
#endif
static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 554dc5b..a196b77 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -77,9 +77,7 @@ struct cgroup_subsys net_cls_subsys = {
.name = "net_cls",
.create = cgrp_create,
.destroy = cgrp_destroy,
-#ifdef CONFIG_NET_CLS_CGROUP
.subsys_id = net_cls_subsys_id,
-#endif
.base_cftypes = ss_files,
.module = THIS_MODULE,
};
@@ -283,12 +281,6 @@ static int __init init_cgroup_cls(void)
if (ret)
goto out;
-#ifndef CONFIG_NET_CLS_CGROUP
- /* We can't use rcu_assign_pointer because this is an int. */
- smp_wmb();
- net_cls_subsys_id = net_cls_subsys.subsys_id;
-#endif
-
ret = register_tcf_proto_ops(&cls_cgroup_ops);
if (ret)
cgroup_unload_subsys(&net_cls_subsys);
@@ -307,11 +299,6 @@ static void __exit exit_cgroup_cls(void)
{
unregister_tcf_proto_ops(&cls_cgroup_ops);
-#ifndef CONFIG_NET_CLS_CGROUP
- net_cls_subsys_id = -1;
- synchronize_rcu();
-#endif
-
#if IS_MODULE(CONFIG_NET_CLS_CGROUP)
static_key_slow_dec(&cgroup_cls_enabled);
rcu_barrier();
--
1.7.12.rc1.16.g05a20c8
--
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