[PATCH v3 0/6] cgroup cls & netprio 'cleanups'

STALE5149d

5 messages, 2 authors, 2012-08-14 · open the first message on its own page

[PATCH v3 0/6] cgroup cls & netprio 'cleanups'

From: Daniel Wagner <hidden>
Date: 2012-08-14 13:02:16

From: Daniel Wagner <redacted>

Hi,

Sorry for the delay on updating this series. The usual
excuse apply here.

I saw that John is busy improving net_prio so I took the
liberty to port his changes to net_cls (#1-3). Patch #3 will
collide with John's unapplied patches. I am happy
to rebase this series if needed. 

Patch #4 and #5 improve the readability with using
IS_MODULE/BUILTIN macros. This patches prepare the last
patch.

Patch #6 removes support for assigning subsystem IDs during
runtime. As it turns out this is not really needed. By doing
so we are able to free some unused memory.

The patches are against net-next.

cheers,
daniel

Cc: "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Cc: Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Eric Dumazet <redacted>
Cc: Gao feng <redacted>
Cc: Glauber Costa <redacted>
Cc: Jamal Hadi Salim <jhs-jkUAjuhPggJWk0Htik3J/w@public.gmane.org>
Cc: John Fastabend <redacted>
Cc: Kamezawa Hiroyuki <redacted>
Cc: Li Zefan <redacted>
Cc: Neil Horman <redacted>
Cc: Tejun Heo <redacted>
Cc: Tim Chen <tim.c.chen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

Daniel Wagner (6):
  cgroup: Move cls function definition to cls_cgroup.h
  cgroup: net_cls rework update socket logic
  cgroup: Update classid for fd pass in SCM_RIGHTS datagramm
  cgroup: Use IS_MODULE/BUITLIN for net_cls
  cgroup: Use IS_MODULE/BUITLIN for net_prio
  cgroup: Assign subsystem IDs during compile time

 include/linux/cgroup.h        | 20 ++++++++++------
 include/linux/cgroup_subsys.h | 24 +++++++++----------
 include/net/cls_cgroup.h      | 36 +++++++++++-----------------
 include/net/netprio_cgroup.h  | 38 +++++++----------------------
 include/net/sock.h            |  8 -------
 kernel/cgroup.c               | 31 +++++++-----------------
 net/core/netprio_cgroup.c     | 19 ++++++---------
 net/core/scm.c                |  7 +++++-
 net/core/sock.c               | 29 ++++++++++++----------
 net/sched/cls_cgroup.c        | 56 +++++++++++++++++++++++++++++++++----------
 net/socket.c                  |  8 -------
 11 files changed, 129 insertions(+), 147 deletions(-)

-- 
1.7.12.rc1.16.g05a20c8

[PATCH v3 1/6] cgroup: Move cls function definition to cls_cgroup.h

From: Daniel Wagner <hidden>
Date: 2012-08-14 13:02:26

From: Daniel Wagner <redacted>

sock_update_classid() is used by net/socket.c which includes
cls_cgroup.h directly.

Signed-off-by: Daniel Wagner <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Li Zefan <redacted>
Cc: Tejun Heo <tj@kernel.org>
Cc: cgroups@vger.kernel.org
Cc: netdev@vger.kernel.org
---
 include/net/cls_cgroup.h | 7 +++++++
 include/net/sock.h       | 8 --------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index a4dc5b0..5f49b69 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h

@@ -24,6 +24,8 @@ struct cgroup_cls_state
 	u32 classid;
 };
 
+extern void sock_update_classid(struct sock *sk);
+
 #ifdef CONFIG_NET_CLS_CGROUP
 static inline u32 task_cls_classid(struct task_struct *p)
 {

@@ -62,9 +64,14 @@ static inline u32 task_cls_classid(struct task_struct *p)
 }
 #endif
 #else
+static inline void sock_update_classid(struct sock *sk)
+{
+}
+
 static inline u32 task_cls_classid(struct task_struct *p)
 {
 	return 0;
 }
 #endif
+
 #endif  /* _NET_CLS_CGROUP_H */

diff --git a/include/net/sock.h b/include/net/sock.h
index 72132ae..160a680 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h

@@ -1486,14 +1486,6 @@ extern void *sock_kmalloc(struct sock *sk, int size,
 extern void sock_kfree_s(struct sock *sk, void *mem, int size);
 extern void sk_send_sigurg(struct sock *sk);
 
-#ifdef CONFIG_CGROUPS
-extern void sock_update_classid(struct sock *sk);
-#else
-static inline void sock_update_classid(struct sock *sk)
-{
-}
-#endif
-
 /*
  * Functions to fill in entries in struct proto_ops when a protocol
  * does not implement a particular function.

-- 
1.7.12.rc1.16.g05a20c8

[PATCH v3 4/6] cgroup: Use IS_MODULE/BUITLIN for net_cls

From: Daniel Wagner <hidden>
Date: 2012-08-14 13:02:29

From: Daniel Wagner <redacted>

Instead of using #ifdef variation for building the net_cls
in the different configuration use explicit IS_MODULE and
IS_BUILTIN macros.

This allows to reorder in readable way the cls_cgroup.h header file
so that the common definition of the struct is first followed
by the two different version for task_cls_classid().

Signed-off-by: Daniel Wagner <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Glauber Costa <redacted>
Cc: Kamezawa Hiroyuki <redacted>
Cc: Li Zefan <redacted>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org
---
 include/net/cls_cgroup.h | 32 ++++++++++++++++++++------------
 net/core/sock.c          |  4 +++-
 net/sched/cls_cgroup.c   |  6 +++---
 3 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index fc05f43..865ea49 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h

@@ -17,7 +17,8 @@
 #include <linux/hardirq.h>
 #include <linux/rcupdate.h>
 
-#ifdef CONFIG_CGROUPS
+#if IS_ENABLED(CONFIG_NET_CLS_CGROUP)
+
 struct cgroup_cls_state
 {
 	struct cgroup_subsys_state css;

@@ -26,7 +27,21 @@ struct cgroup_cls_state
 
 extern void sock_update_classid(struct sock *sk, struct task_struct *task);
 
-#ifdef CONFIG_NET_CLS_CGROUP
+#else
+
+static inline void sock_update_classid(struct sock *sk, struct task_struct *task)
+{
+}
+
+static inline u32 task_cls_classid(struct task_struct *p)
+{
+	return 0;
+}
+
+#endif
+
+#if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)
+
 static inline u32 task_cls_classid(struct task_struct *p)
 {
 	int classid;

@@ -38,7 +53,9 @@ static inline u32 task_cls_classid(struct task_struct *p)
 
 	return classid;
 }
-#else
+
+#elif IS_MODULE(CONFIG_NET_CLS_CGROUP)
+
 extern int net_cls_subsys_id;
 
 static inline u32 task_cls_classid(struct task_struct *p)

@@ -56,16 +73,7 @@ static inline u32 task_cls_classid(struct task_struct *p)
 
 	return classid;
 }
-#endif
-#else
-static inline void sock_update_classid(struct sock *sk, struct task_struct *task)
-{
-}
 
-static inline u32 task_cls_classid(struct task_struct *p)
-{
-	return 0;
-}
 #endif
 
 #endif  /* _NET_CLS_CGROUP_H */

diff --git a/net/core/sock.c b/net/core/sock.c
index e08df6b..d2d920e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c

@@ -327,7 +327,7 @@ int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 EXPORT_SYMBOL(__sk_backlog_rcv);
 
 #if defined(CONFIG_CGROUPS)
-#if !defined(CONFIG_NET_CLS_CGROUP)
+#if IS_MODULE(CONFIG_NET_CLS_CGROUP)
 int net_cls_subsys_id = -1;
 EXPORT_SYMBOL_GPL(net_cls_subsys_id);
 #endif

@@ -1223,6 +1223,7 @@ static void sk_prot_free(struct proto *prot, struct sock *sk)
 }
 
 #ifdef CONFIG_CGROUPS
+#if IS_ENABLED(CONFIG_NET_CLS_CGROUP)
 void sock_update_classid(struct sock *sk, struct task_struct *task)
 {
 	u32 classid;

@@ -1235,6 +1236,7 @@ void sock_update_classid(struct sock *sk, struct task_struct *task)
 		sk->sk_classid = classid;
 }
 EXPORT_SYMBOL(sock_update_classid);
+#endif
 
 void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
 {

diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 3535771..9ffe9b5 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c

@@ -115,7 +115,7 @@ struct cgroup_subsys net_cls_subsys = {
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
 	.attach		= cgrp_attach,
-#ifdef CONFIG_NET_CLS_CGROUP
+#if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)
 	.subsys_id	= net_cls_subsys_id,
 #endif
 	.base_cftypes	= ss_files,

@@ -321,7 +321,7 @@ static int __init init_cgroup_cls(void)
 	if (ret)
 		goto out;
 
-#ifndef CONFIG_NET_CLS_CGROUP
+#if IS_MODULE(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;

@@ -339,7 +339,7 @@ static void __exit exit_cgroup_cls(void)
 {
 	unregister_tcf_proto_ops(&cls_cgroup_ops);
 
-#ifndef CONFIG_NET_CLS_CGROUP
+#if IS_MODULE(CONFIG_NET_CLS_CGROUP)
 	net_cls_subsys_id = -1;
 	synchronize_rcu();
 #endif

-- 
1.7.12.rc1.16.g05a20c8

[PATCH v3 5/6] cgroup: Use IS_MODULE/BUITLIN for net_prio

From: Daniel Wagner <hidden>
Date: 2012-08-14 13:02:30

From: Daniel Wagner <redacted>

Instead of using #ifdef variation for building the net_prio
in the different configuration use explicit IS_MODULE and
IS_BUILTIN macros.

This allows to reorder in readable way the netprio_cgroup.h header file
so that the common definition of the struct is first followed
by the two different version for task_netprioidx().

Signed-off-by: Daniel Wagner <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Glauber Costa <redacted>
Cc: Kamezawa Hiroyuki <redacted>
Cc: Li Zefan <redacted>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org
---
 include/net/netprio_cgroup.h | 33 ++++++++++++++++-----------------
 net/core/netprio_cgroup.c    |  6 +++---
 net/core/sock.c              |  4 +++-
 3 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/include/net/netprio_cgroup.h b/include/net/netprio_cgroup.h
index 2719dec..c43461e 100644
--- a/include/net/netprio_cgroup.h
+++ b/include/net/netprio_cgroup.h

@@ -17,6 +17,7 @@
 #include <linux/hardirq.h>
 #include <linux/rcupdate.h>
 
+#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
 
 struct netprio_map {
 	struct rcu_head rcu;

@@ -24,19 +25,26 @@ struct netprio_map {
 	u32 priomap[];
 };
 
-#ifdef CONFIG_CGROUPS
-
 struct cgroup_netprio_state {
 	struct cgroup_subsys_state css;
 	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);
 
+#else
+
+static inline void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
+{
+}
+
+static inline u32 task_netprioidx(struct task_struct *p)
+{
+	return 0;
+}
+
+#endif
+
 #if IS_BUILTIN(CONFIG_NETPRIO_CGROUP)
 
 static inline u32 task_netprioidx(struct task_struct *p)

@@ -54,6 +62,8 @@ static inline u32 task_netprioidx(struct task_struct *p)
 
 #elif IS_MODULE(CONFIG_NETPRIO_CGROUP)
 
+extern int net_prio_subsys_id;
+
 static inline u32 task_netprioidx(struct task_struct *p)
 {
 	struct cgroup_netprio_state *state;

@@ -72,17 +82,6 @@ static inline u32 task_netprioidx(struct task_struct *p)
 	return idx;
 }
 
-#else
-
-static inline u32 task_netprioidx(struct task_struct *p)
-{
-	return 0;
-}
-
 #endif /* CONFIG_NETPRIO_CGROUP */
 
-#else
-#define sock_update_netprioidx(sk, task)
-#endif
-
 #endif  /* _NET_CLS_CGROUP_H */

diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 98478aa..238ece6 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c

@@ -342,7 +342,7 @@ struct cgroup_subsys net_prio_subsys = {
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
 	.attach		= net_prio_attach,
-#ifdef CONFIG_NETPRIO_CGROUP
+#if IS_BUILTIN(CONFIG_NETPRIO_CGROUP)
 	.subsys_id	= net_prio_subsys_id,
 #endif
 	.base_cftypes	= ss_files,

@@ -382,7 +382,7 @@ static int __init init_cgroup_netprio(void)
 	ret = cgroup_load_subsys(&net_prio_subsys);
 	if (ret)
 		goto out;
-#ifndef CONFIG_NETPRIO_CGROUP
+#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
 	smp_wmb();
 	net_prio_subsys_id = net_prio_subsys.subsys_id;
 #endif

@@ -402,7 +402,7 @@ static void __exit exit_cgroup_netprio(void)
 
 	cgroup_unload_subsys(&net_prio_subsys);
 
-#ifndef CONFIG_NETPRIO_CGROUP
+#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
 	net_prio_subsys_id = -1;
 	synchronize_rcu();
 #endif

diff --git a/net/core/sock.c b/net/core/sock.c
index d2d920e..bdd06af 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c

@@ -331,7 +331,7 @@ EXPORT_SYMBOL(__sk_backlog_rcv);
 int net_cls_subsys_id = -1;
 EXPORT_SYMBOL_GPL(net_cls_subsys_id);
 #endif
-#if !defined(CONFIG_NETPRIO_CGROUP)
+#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
 int net_prio_subsys_id = -1;
 EXPORT_SYMBOL_GPL(net_prio_subsys_id);
 #endif

@@ -1238,6 +1238,7 @@ void sock_update_classid(struct sock *sk, struct task_struct *task)
 EXPORT_SYMBOL(sock_update_classid);
 #endif
 
+#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
 void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
 {
 	if (in_interrupt())

@@ -1247,6 +1248,7 @@ void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
 }
 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
 #endif
+#endif
 
 /**
  *	sk_alloc - All socket objects are allocated here

-- 
1.7.12.rc1.16.g05a20c8

[PATCH v3 6/6] cgroup: Assign subsystem IDs during compile time

From: Daniel Wagner <hidden>
Date: 2012-08-14 13:02:30

From: Daniel Wagner <redacted>

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 12 + 1 at max (at this point there are 12
subsystem). The additinal one is the price we have to pay to
distinguish between builtin and module subsystems.

We should only access task_cls_classid() and task_netprioidx()
if the subsystem is ready to be used using jump labels for this.

Signed-off-by: Daniel Wagner <redacted>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Gao feng <redacted>
Cc: Glauber Costa <redacted>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <redacted>
Cc: Kamezawa Hiroyuki <redacted>
Cc: Li Zefan <redacted>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: netdev@vger.kernel.org
Cc: cgroups@vger.kernel.org
---
 include/linux/cgroup.h        | 20 +++++++++++++-------
 include/linux/cgroup_subsys.h | 24 ++++++++++++------------
 include/net/cls_cgroup.h      | 41 ++++++++++++-----------------------------
 include/net/netprio_cgroup.h  | 43 ++++++++++++-------------------------------
 kernel/cgroup.c               | 31 +++++++++----------------------
 net/core/netprio_cgroup.c     | 17 ++++++-----------
 net/core/sock.c               | 14 ++++++--------
 net/sched/cls_cgroup.c        | 18 +++++-------------
 8 files changed, 75 insertions(+), 133 deletions(-)

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index c90eaa8..995739f 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h

@@ -46,16 +46,20 @@ extern const struct file_operations proc_cgroup_operations;
 /* Define the enumeration of all builtin cgroup subsystems */
 #define SUBSYS(_x) _x ## _subsys_id,
 enum cgroup_subsys_id {
+
+#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option)
+#include <linux/cgroup_subsys.h>
+#undef IS_SUBSYS_ENABLED
+
+	CGROUP_BUILTIN_SUBSYS_COUNT,
+
+#define IS_SUBSYS_ENABLED(option) IS_MODULE(option)
 #include <linux/cgroup_subsys.h>
-	CGROUP_BUILTIN_SUBSYS_COUNT
+#undef IS_SUBSYS_ENABLED
+
+	CGROUP_SUBSYS_COUNT
 };
 #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))
 
 /* Per-subsystem/per-cgroup state maintained by the system. */
 struct cgroup_subsys_state {

@@ -521,7 +525,9 @@ 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 IS_SUBSYS_ENABLED
 #undef SUBSYS
 
 static inline struct cgroup_subsys_state *cgroup_subsys_state(

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 865ea49..7834fd7 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h

@@ -16,6 +16,7 @@
 #include <linux/cgroup.h>
 #include <linux/hardirq.h>
 #include <linux/rcupdate.h>
+#include <linux/jump_label.h>
 
 #if IS_ENABLED(CONFIG_NET_CLS_CGROUP)

@@ -25,27 +26,18 @@ struct cgroup_cls_state
 	u32 classid;
 };
 
-extern void sock_update_classid(struct sock *sk, struct task_struct *task);
-
-#else
-
-static inline void sock_update_classid(struct sock *sk, struct task_struct *task)
-{
-}
-
-static inline u32 task_cls_classid(struct task_struct *p)
-{
-	return 0;
-}
-
-#endif
+extern struct static_key cgroup_cls_enabled;
+#define clscg_enabled static_key_false(&cgroup_cls_enabled)
 
-#if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)
+extern void sock_update_classid(struct sock *sk, struct task_struct *task);
 
 static inline u32 task_cls_classid(struct task_struct *p)
 {
 	int classid;
 
+	if (!clscg_enabled)
+		return 0;
+
 	rcu_read_lock();
 	classid = container_of(task_subsys_state(p, net_cls_subsys_id),
 			       struct cgroup_cls_state, css)->classid;

@@ -54,24 +46,15 @@ static inline u32 task_cls_classid(struct task_struct *p)
 	return classid;
 }
 
-#elif IS_MODULE(CONFIG_NET_CLS_CGROUP)
+#else
 
-extern int net_cls_subsys_id;
+static inline void sock_update_classid(struct sock *sk, struct task_struct *task)
+{
+}
 
 static inline u32 task_cls_classid(struct task_struct *p)
 {
-	int id;
-	u32 classid = 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;
-	rcu_read_unlock();
-
-	return classid;
+	return 0;
 }
 
 #endif

diff --git a/include/net/netprio_cgroup.h b/include/net/netprio_cgroup.h
index c43461e..4ebdae6 100644
--- a/include/net/netprio_cgroup.h
+++ b/include/net/netprio_cgroup.h

@@ -16,6 +16,7 @@
 #include <linux/cgroup.h>
 #include <linux/hardirq.h>
 #include <linux/rcupdate.h>
+#include <linux/jump_label.h>
 
 #if IS_ENABLED(CONFIG_NETPRIO_CGROUP)

@@ -30,28 +31,19 @@ struct cgroup_netprio_state {
 	u32 prioidx;
 };
 
-extern void sock_update_netprioidx(struct sock *sk, struct task_struct *task);
-
-#else
-
-static inline void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
-{
-}
-
-static inline u32 task_netprioidx(struct task_struct *p)
-{
-	return 0;
-}
-
-#endif
+extern struct static_key cgroup_netprio_enabled;
+#define netpriocg_enabled static_key_false(&cgroup_netprio_enabled)
 
-#if IS_BUILTIN(CONFIG_NETPRIO_CGROUP)
+extern void sock_update_netprioidx(struct sock *sk, struct task_struct *task);
 
 static inline u32 task_netprioidx(struct task_struct *p)
 {
 	struct cgroup_netprio_state *state;
 	u32 idx;
 
+	if (!netpriocg_enabled)
+		return 0;
+
 	rcu_read_lock();
 	state = container_of(task_subsys_state(p, net_prio_subsys_id),
 			     struct cgroup_netprio_state, css);

@@ -60,26 +52,15 @@ static inline u32 task_netprioidx(struct task_struct *p)
 	return idx;
 }
 
-#elif IS_MODULE(CONFIG_NETPRIO_CGROUP)
+#else
 
-extern int net_prio_subsys_id;
+static inline void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
+{
+}
 
 static inline u32 task_netprioidx(struct task_struct *p)
 {
-	struct cgroup_netprio_state *state;
-	int subsys_id;
-	u32 idx = 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;
-	}
-	rcu_read_unlock();
-	return idx;
+	return 0;
 }
 
 #endif /* CONFIG_NETPRIO_CGROUP */

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 7981850..aa629ce 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c

@@ -93,9 +93,12 @@ 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

@@ -1307,7 +1310,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 		 * raced with a module_delete call, and to the user this is
 		 * essentially a "subsystem doesn't exist" case.
 		 */
-		for (i--; i >= CGROUP_BUILTIN_SUBSYS_COUNT; i--) {
+		for (i--; i > CGROUP_BUILTIN_SUBSYS_COUNT; i--) {
 			/* drop refcounts only on the ones we took */
 			unsigned long bit = 1UL << i;

@@ -1324,7 +1327,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 static void drop_parsed_module_refcounts(unsigned long subsys_bits)
 {
 	int i;
-	for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) {
+	for (i = CGROUP_BUILTIN_SUBSYS_COUNT + 1; i < CGROUP_SUBSYS_COUNT; i++) {
 		unsigned long bit = 1UL << i;
 
 		if (!(bit & subsys_bits))

@@ -4322,7 +4325,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
 	 */
 	if (ss->module == NULL) {
 		/* a few sanity checks */
-		BUG_ON(ss->subsys_id >= CGROUP_BUILTIN_SUBSYS_COUNT);
+		BUG_ON(ss->subsys_id > CGROUP_BUILTIN_SUBSYS_COUNT);
 		BUG_ON(subsys[ss->subsys_id] != ss);
 		return 0;
 	}

@@ -4330,24 +4333,8 @@ 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 = CGROUP_BUILTIN_SUBSYS_COUNT; 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

@@ -4356,7 +4343,7 @@ 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);
 	}

@@ -4372,7 +4359,7 @@ 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 238ece6..c3f93a1 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c

@@ -155,6 +155,9 @@ static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp)
 		goto out;
 	}
 
+	if (!netpriocg_enabled && !cgrp->parent)
+                static_key_slow_inc(&cgroup_netprio_enabled);
+
 	ret = update_netdev_tables();
 	if (ret < 0) {
 		put_prioidx(cs->prioidx);

@@ -173,6 +176,9 @@ static void cgrp_destroy(struct cgroup *cgrp)
 	struct net_device *dev;
 	struct netprio_map *map;
 
+        if (netpriocg_enabled && !cgrp->parent)
+                static_key_slow_dec(&cgroup_netprio_enabled);
+
 	cs = cgrp_netprio_state(cgrp);
 	rtnl_lock();
 	for_each_netdev(&init_net, dev) {

@@ -342,9 +348,7 @@ struct cgroup_subsys net_prio_subsys = {
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
 	.attach		= net_prio_attach,
-#if IS_BUILTIN(CONFIG_NETPRIO_CGROUP)
 	.subsys_id	= net_prio_subsys_id,
-#endif
 	.base_cftypes	= ss_files,
 	.module		= THIS_MODULE
 };

@@ -382,10 +386,6 @@ static int __init init_cgroup_netprio(void)
 	ret = cgroup_load_subsys(&net_prio_subsys);
 	if (ret)
 		goto out;
-#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
-	smp_wmb();
-	net_prio_subsys_id = net_prio_subsys.subsys_id;
-#endif
 
 	register_netdevice_notifier(&netprio_device_notifier);

@@ -402,11 +402,6 @@ static void __exit exit_cgroup_netprio(void)
 
 	cgroup_unload_subsys(&net_prio_subsys);
 
-#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
-	net_prio_subsys_id = -1;
-	synchronize_rcu();
-#endif
-
 	rtnl_lock();
 	for_each_netdev(&init_net, dev) {
 		old = rtnl_dereference(dev->priomap);

diff --git a/net/core/sock.c b/net/core/sock.c
index bdd06af..301243b 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c

@@ -326,15 +326,13 @@ int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 }
 EXPORT_SYMBOL(__sk_backlog_rcv);
 
-#if defined(CONFIG_CGROUPS)
-#if IS_MODULE(CONFIG_NET_CLS_CGROUP)
-int net_cls_subsys_id = -1;
-EXPORT_SYMBOL_GPL(net_cls_subsys_id);
-#endif
-#if IS_MODULE(CONFIG_NETPRIO_CGROUP)
-int net_prio_subsys_id = -1;
-EXPORT_SYMBOL_GPL(net_prio_subsys_id);
+#if IS_ENABLED(CONFIG_NET_CLS_CGROUP)
+struct static_key cgroup_cls_enabled = STATIC_KEY_INIT_FALSE;
+EXPORT_SYMBOL_GPL(cgroup_cls_enabled);
 #endif
+#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
+struct static_key cgroup_netprio_enabled = STATIC_KEY_INIT_FALSE;
+EXPORT_SYMBOL_GPL(cgroup_netprio_enabled);
 #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 9ffe9b5..80f71cd 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c

@@ -45,12 +45,17 @@ static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp)
 
 	if (cgrp->parent)
 		cs->classid = cgrp_cls_state(cgrp->parent)->classid;
+	else if (!clscg_enabled)
+                static_key_slow_inc(&cgroup_cls_enabled);
 
 	return &cs->css;
 }
 
 static void cgrp_destroy(struct cgroup *cgrp)
 {
+	if (!cgrp->parent && clscg_enabled)
+                static_key_slow_dec(&cgroup_cls_enabled);
+
 	kfree(cgrp_cls_state(cgrp));
 }

@@ -115,9 +120,7 @@ struct cgroup_subsys net_cls_subsys = {
 	.create		= cgrp_create,
 	.destroy	= cgrp_destroy,
 	.attach		= cgrp_attach,
-#if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)
 	.subsys_id	= net_cls_subsys_id,
-#endif
 	.base_cftypes	= ss_files,
 	.module		= THIS_MODULE,
 };

@@ -321,12 +324,6 @@ static int __init init_cgroup_cls(void)
 	if (ret)
 		goto out;
 
-#if IS_MODULE(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);

@@ -339,11 +336,6 @@ static void __exit exit_cgroup_cls(void)
 {
 	unregister_tcf_proto_ops(&cls_cgroup_ops);
 
-#if IS_MODULE(CONFIG_NET_CLS_CGROUP)
-	net_cls_subsys_id = -1;
-	synchronize_rcu();
-#endif
-
 	cgroup_unload_subsys(&net_cls_subsys);
 }

-- 
1.7.12.rc1.16.g05a20c8

`h`	back out one level
`j`	next message in thread
`k`	previous message in thread
`l`	drill in
`Esc`	close help / fold thread tree
`?`	toggle this help