[PATCH 14/24] net, diet: Make MIB statistics collections depend on PROC_FS

[Andi Kleen <andi@firstfloor.org>]

From: Andi Kleen <ak@linux.intel.com>

When PROC_FS is not compiled in we don't need the statistics
gathering code, as the only way to see the output is through
/proc. Saves about 5k text, likely more in dynamic memory.

   text    data     bss     dec     hex filename
 386302    8993   12564  407859   63933 net/built-in.o-with-mib
 381542    8933   12564  403039   6265f net/built-in.o-wo-mib

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 include/net/ip.h         |  9 ++++++++
 include/net/ipv6.h       |  8 ++++++-
 include/net/snmp.h       | 60 ++++++++++++++++++++++++++++++++++++++++--------
 net/ipv4/af_inet.c       | 12 ++++++++++
 net/ipv6/addrconf.c      |  9 ++++++++
 net/ipv6/addrconf_core.c |  2 ++
 net/ipv6/af_inet6.c      |  5 ++++
 7 files changed, 95 insertions(+), 10 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index 3ec2b0f..6764e30 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -196,6 +196,7 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
 
+#ifdef CONFIG_PROC_FS
 unsigned long snmp_fold_field(void __percpu *mib[], int offt);
 #if BITS_PER_LONG==32
 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
@@ -217,6 +218,12 @@ static inline void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
 		ptr[i] = NULL;
 	}
 }
+#else
+#define snmp_mib_init(a,b,c) ({ 0; })
+#define snmp_mib_free(x) do {} while (0)
+#define snmp_fold_field(a, b) ({ 0; })
+#define snmp_fold_field64(a, b, c) ({ 0; })
+#endif
 
 void inet_get_local_port_range(struct net *net, int *low, int *high);
 
@@ -523,6 +530,8 @@ void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 
 #ifdef CONFIG_PROC_FS
 int ip_misc_proc_init(void);
+#else
+static inline int ip_misc_proc_init(void) { return 0; }
 #endif
 
 #endif	/* _IP_H */
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index d640925..3c4c041 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -830,11 +830,17 @@ int udp6_proc_init(struct net *net);
 void udp6_proc_exit(struct net *net);
 int udplite6_proc_init(void);
 void udplite6_proc_exit(void);
+#ifdef CONFIG_PROC_FS
 int ipv6_misc_proc_init(void);
 void ipv6_misc_proc_exit(void);
 int snmp6_register_dev(struct inet6_dev *idev);
 int snmp6_unregister_dev(struct inet6_dev *idev);
-
+#else
+static inline int ipv6_misc_proc_init(void) { return 0; }
+static inline void ipv6_misc_proc_exit(void) {}
+static inline int snmp6_register_dev(struct inet6_dev *idev) { return 0; }
+static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
+#endif
 #else
 static inline int ac6_proc_init(struct net *net) { return 0; }
 static inline void ac6_proc_exit(struct net *net) { }
diff --git a/include/net/snmp.h b/include/net/snmp.h
index 7159626..83815f9 100644
--- a/include/net/snmp.h
+++ b/include/net/snmp.h
@@ -23,6 +23,8 @@
 #include <linux/snmp.h>
 #include <linux/smp.h>
 
+#define MIB_SIZE(x) (IS_ENABLED(CONFIG_PROC_FS) ? (x) : (0))
+
 /*
  * Mibs are stored in array of unsigned long.
  */
@@ -31,6 +33,7 @@
  *  - list of entries for particular API (such as /proc/net/snmp)
  *  - name of entries.
  */
+#ifdef CONFIG_PROC_FS
 struct snmp_mib {
 	const char *name;
 	int entry;
@@ -45,6 +48,11 @@ struct snmp_mib {
 	.name = NULL,		\
 	.entry = 0,		\
 }
+#else
+struct snmp_mib {};
+#define SNMP_MIB_ITEM(_name,_entry) {}
+#define SNMP_MIB_SENTINEL
+#endif
 
 /*
  * We use unsigned longs for most mibs but u64 for ipstats.
@@ -52,7 +60,7 @@ struct snmp_mib {
 #include <linux/u64_stats_sync.h>
 
 /* IPstats */
-#define IPSTATS_MIB_MAX	__IPSTATS_MIB_MAX
+#define IPSTATS_MIB_MAX MIB_SIZE(__IPSTATS_MIB_MAX)
 struct ipstats_mib {
 	/* mibs[] must be first field of struct ipstats_mib */
 	u64		mibs[IPSTATS_MIB_MAX];
@@ -60,18 +68,18 @@ struct ipstats_mib {
 };
 
 /* ICMP */
-#define ICMP_MIB_MAX	__ICMP_MIB_MAX
+#define ICMP_MIB_MAX	MIB_SIZE(__ICMP_MIB_MAX)
 struct icmp_mib {
 	unsigned long	mibs[ICMP_MIB_MAX];
 };
 
-#define ICMPMSG_MIB_MAX	__ICMPMSG_MIB_MAX
+#define ICMPMSG_MIB_MAX	MIB_SIZE(__ICMPMSG_MIB_MAX)
 struct icmpmsg_mib {
 	atomic_long_t	mibs[ICMPMSG_MIB_MAX];
 };
 
 /* ICMP6 (IPv6-ICMP) */
-#define ICMP6_MIB_MAX	__ICMP6_MIB_MAX
+#define ICMP6_MIB_MAX	MIB_SIZE(__ICMP6_MIB_MAX)
 /* per network ns counters */
 struct icmpv6_mib {
 	unsigned long	mibs[ICMP6_MIB_MAX];
@@ -81,7 +89,7 @@ struct icmpv6_mib_device {
 	atomic_long_t	mibs[ICMP6_MIB_MAX];
 };
 
-#define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
+#define ICMP6MSG_MIB_MAX  MIB_SIZE(__ICMP6MSG_MIB_MAX)
 /* per network ns counters */
 struct icmpv6msg_mib {
 	atomic_long_t	mibs[ICMP6MSG_MIB_MAX];
@@ -93,29 +101,31 @@ struct icmpv6msg_mib_device {
 
 
 /* TCP */
-#define TCP_MIB_MAX	__TCP_MIB_MAX
+#define TCP_MIB_MAX	MIB_SIZE(__TCP_MIB_MAX)
 struct tcp_mib {
 	unsigned long	mibs[TCP_MIB_MAX];
 };
 
 /* UDP */
-#define UDP_MIB_MAX	__UDP_MIB_MAX
+#define UDP_MIB_MAX	MIB_SIZE(__UDP_MIB_MAX)
 struct udp_mib {
 	unsigned long	mibs[UDP_MIB_MAX];
 };
 
 /* Linux */
-#define LINUX_MIB_MAX	__LINUX_MIB_MAX
+#define LINUX_MIB_MAX	MIB_SIZE(__LINUX_MIB_MAX)
 struct linux_mib {
 	unsigned long	mibs[LINUX_MIB_MAX];
 };
 
 /* Linux Xfrm */
-#define LINUX_MIB_XFRMMAX	__LINUX_MIB_XFRMMAX
+#define LINUX_MIB_XFRMMAX	MIB_SIZE(__LINUX_MIB_XFRMMAX)
 struct linux_xfrm_mib {
 	unsigned long	mibs[LINUX_MIB_XFRMMAX];
 };
 
+#ifdef CONFIG_PROC_FS
+
 #define SNMP_ARRAY_SZ 1
 
 #define DEFINE_SNMP_STAT(type, name)	\
@@ -216,4 +226,36 @@ struct linux_xfrm_mib {
 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend) SNMP_UPD_PO_STATS_BH(mib, basefield, addend)
 #endif
 
+#else
+
+/* Stub out everything */
+
+#define SNMP_ARRAY_SZ 0
+#define DEFINE_SNMP_STAT(type, name) type *name
+#define DEFINE_SNMP_STAT_ATOMIC(type, name) type *name
+#define DECLARE_SNMP_STAT(type, name) extern type *name
+#define SNMP_INC_STATS_BH(mib, field) do { (void)(mib); } while(0)
+#define SNMP_INC_STATS_USER(mib, field) do { (void)(mib); } while(0)
+#define SNMP_INC_STATS_ATOMIC_LONG(mib, field) do { (void)(mib); } while(0)
+#define SNMP_INC_STATS(mib, field) do { (void)(mib); } while(0)
+#define SNMP_DEC_STATS(mib, field) do { (void)(mib); } while(0)
+#define SNMP_ADD_STATS_BH(mib, field, addend) do { (void)(mib); } while(0)
+#define SNMP_ADD_STATS_USER(mib, field, addend)	do { (void)(mib); } while(0)
+#define SNMP_ADD_STATS(mib, field, addend) do { (void)(mib); } while(0)
+#define SNMP_UPD_PO_STATS(mib, basefield, addend) do { (void)(mib); } while(0)
+#define SNMP_UPD_PO_STATS_BH(mib, basefield, addend) \
+	do { (void)(mib); } while(0)
+#define SNMP_ADD_STATS64_BH(mib, field, addend) do { (void)(mib); } while(0)
+#define SNMP_ADD_STATS64_USER(mib, field, addend) do { (void)(mib); } while(0)
+#define SNMP_ADD_STATS64(mib, field, addend) do { (void)(mib); } while(0)
+#define SNMP_INC_STATS64_BH(mib, field) do { (void)(mib); } while(0)
+#define SNMP_INC_STATS64_USER(mib, field) do { (void)(mib); } while(0)
+#define SNMP_INC_STATS64(mib, field) do { (void)(mib); } while(0)
+#define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend) \
+	do { (void)(mib); } while(0)
+#define SNMP_UPD_PO_STATS64(mib, basefield, addend) \
+	do { (void)(mib); } while(0)
+
+#endif /* CONFIG_NET_SNMP */
+
 #endif
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index e65e750..46b1815 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1482,6 +1482,8 @@ int inet_ctl_sock_create(struct sock **sk, unsigned short family,
 }
 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
 
+#ifdef CONFIG_PROC_FS
+
 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
 {
 	unsigned long res = 0;
@@ -1541,6 +1543,8 @@ int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
 }
 EXPORT_SYMBOL_GPL(snmp_mib_init);
 
+#endif
+
 #ifdef CONFIG_IP_MULTICAST
 static const struct net_protocol igmp_protocol = {
 	.handler =	igmp_rcv,
@@ -1572,6 +1576,7 @@ static const struct net_protocol icmp_protocol = {
 	.netns_ok =	1,
 };
 
+#ifdef CONFIG_PROC_FS
 static __net_init int ipv4_mib_init_net(struct net *net)
 {
 	int i;
@@ -1656,6 +1661,13 @@ static int __init init_ipv4_mibs(void)
 	return register_pernet_subsys(&ipv4_mib_ops);
 }
 
+#else
+static int __init init_ipv4_mibs(void)
+{
+	return 0;
+}
+#endif
+
 static int ipv4_proc_init(void);
 
 #ifdef CONFIG_IP_OFFLOAD
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6c7fa08..0d8c820 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -271,6 +271,7 @@ static void addrconf_mod_dad_work(struct inet6_ifaddr *ifp,
 	mod_delayed_work(addrconf_wq, &ifp->dad_work, delay);
 }
 
+#ifdef CONFIG_PROC_FS
 static int snmp6_alloc_dev(struct inet6_dev *idev)
 {
 	int i;
@@ -309,6 +310,9 @@ err_icmp:
 err_ip:
 	return -ENOMEM;
 }
+#else
+static int snmp6_alloc_dev(struct inet6_dev *idev) { return 0; }
+#endif
 
 static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
 {
@@ -4348,6 +4352,7 @@ static inline size_t inet6_if_nlmsg_size(void)
 	       + nla_total_size(inet6_ifla6_size()); /* IFLA_PROTINFO */
 }
 
+#ifdef CONFIG_PROC_FS
 static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
 				      int items, int bytes)
 {
@@ -4391,6 +4396,10 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype,
 		break;
 	}
 }
+#else
+static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype,
+			     int bytes) {}
+#endif
 
 static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev)
 {
diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c
index 4c11cbc..80ff00e 100644
--- a/net/ipv6/addrconf_core.c
+++ b/net/ipv6/addrconf_core.c
@@ -121,9 +121,11 @@ EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
 
 static void snmp6_free_dev(struct inet6_dev *idev)
 {
+#ifdef CONFIG_PROC_FS
 	kfree(idev->stats.icmpv6msgdev);
 	kfree(idev->stats.icmpv6dev);
 	snmp_mib_free((void __percpu **)idev->stats.ipv6);
+#endif
 }
 
 /* Nobody refers to this device, we may destroy it. */
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 68ac214..9ff80ad 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -711,6 +711,7 @@ static void ipv6_packet_cleanup(void)
 	dev_remove_pack(&ipv6_packet_type);
 }
 
+#ifdef CONFIG_PROC_FS
 static int __net_init ipv6_init_mibs(struct net *net)
 {
 	int i;
@@ -768,6 +769,10 @@ static void ipv6_cleanup_mibs(struct net *net)
 	snmp_mib_free((void __percpu **)net->mib.icmpv6_statistics);
 	kfree(net->mib.icmpv6msg_statistics);
 }
+#else
+static inline int __net_init ipv6_init_mibs(struct net *net) { return 0; }
+static inline void ipv6_cleanup_mibs(struct net *net) {}
+#endif
 
 static int __net_init inet6_net_init(struct net *net)
 {
-- 
1.9.0