[PATCH net-next 0/4] net: extend indirect calls helper usage

[PATCH net-next 0/4] net: extend indirect calls helper usage

[Paolo Abeni]

This series applies the indirect calls helper introduced with commit 
283c16a2dfd3 ("indirect call wrappers: helpers to speed-up indirect 
calls of builtin") to more hooks inside the network stack.

Overall this avoids up to 4 indirect calls for each RX packets,
giving small but measurable gain TCP_RR workloads and 5% under UDP
flood.

Paolo Abeni (4):
  net: use indirect calls helpers for ptype hook
  net: use indirect calls helpers for L3 handler hooks
  net: use indirect calls helpers at early demux stage
  net: use indirect calls helpers at the socket layer

 net/core/dev.c       |  6 ++++--
 net/ipv4/ip_input.c  | 11 +++++++++--
 net/ipv6/ip6_input.c | 12 ++++++++++--
 net/ipv6/tcp_ipv6.c  |  5 +++--
 net/ipv6/udp.c       |  5 +++--
 net/socket.c         | 20 ++++++++++++++++----
 6 files changed, 45 insertions(+), 14 deletions(-)

-- 
2.20.1

[PATCH net-next 1/4] net: use indirect calls helpers for ptype hook

[Paolo Abeni]

This avoids an indirect call per RX IPv6/IPv4 packet.
Note that we don't want to use the indirect calls helper for taps.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/core/dev.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 22f2640f559a..108ac8137b9b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4987,7 +4987,8 @@ static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
 
 	ret = __netif_receive_skb_core(skb, pfmemalloc, &pt_prev);
 	if (pt_prev)
-		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
+					 skb->dev, pt_prev, orig_dev);
 	return ret;
 }
 
@@ -5033,7 +5034,8 @@ static inline void __netif_receive_skb_list_ptype(struct list_head *head,
 	else
 		list_for_each_entry_safe(skb, next, head, list) {
 			skb_list_del_init(skb);
-			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+			INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
+					   skb->dev, pt_prev, orig_dev);
 		}
 }
 
-- 
2.20.1

Re: [PATCH net-next 1/4] net: use indirect calls helpers for ptype hook

[Eric Dumazet]

On 5/3/19 8:01 AM, Paolo Abeni wrote:
> This avoids an indirect call per RX IPv6/IPv4 packet.
> Note that we don't want to use the indirect calls helper for taps.
> 
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
>  net/core/dev.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 22f2640f559a..108ac8137b9b 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -4987,7 +4987,8 @@ static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
>  
>  	ret = __netif_receive_skb_core(skb, pfmemalloc, &pt_prev);
>  	if (pt_prev)
> -		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
> +		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
> +					 skb->dev, pt_prev, orig_dev);
>  	return ret;
>  }
>  
> @@ -5033,7 +5034,8 @@ static inline void __netif_receive_skb_list_ptype(struct list_head *head,
>  	else
>  		list_for_each_entry_safe(skb, next, head, list) {
>  			skb_list_del_init(skb);
> -			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
> +			INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
> +					   skb->dev, pt_prev, orig_dev);

IPv4 has ip_list_rcv() and IPv6 has ipv6_list_rcv(),
so the code  invoking ->list_func() should run,
meaning this part of the patch was not needed.

if (pt_prev->list_func != NULL)
    pt_prev->list_func(head, pt_prev, orig_dev);

Maybe you want instead have INDIRECT_CALL_INET() for the list_func() calls.

[PATCH net-next 2/4] net: use indirect calls helpers for L3 handler hooks

[Paolo Abeni]

So that we avoid another indirect call per RX packet in the common
case.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/ipv4/ip_input.c  | 6 +++++-
 net/ipv6/ip6_input.c | 7 ++++++-
 net/ipv6/tcp_ipv6.c  | 3 ++-
 net/ipv6/udp.c       | 3 ++-
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 1132d6d1796a..8d78de4b0304 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -130,6 +130,7 @@
 #include <linux/inetdevice.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
+#include <linux/indirect_call_wrapper.h>
 
 #include <net/snmp.h>
 #include <net/ip.h>
@@ -188,6 +189,8 @@ bool ip_call_ra_chain(struct sk_buff *skb)
 	return false;
 }
 
+INDIRECT_CALLABLE_DECLARE(int udp_rcv(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int tcp_v4_rcv(struct sk_buff *));
 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol)
 {
 	const struct net_protocol *ipprot;
@@ -205,7 +208,8 @@ void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol)
 			}
 			nf_reset(skb);
 		}
-		ret = ipprot->handler(skb);
+		ret = INDIRECT_CALL_2(ipprot->handler, tcp_v4_rcv, udp_rcv,
+				      skb);
 		if (ret < 0) {
 			protocol = -ret;
 			goto resubmit;
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index c7ed2b6d5a1d..adf06159837f 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -29,6 +29,7 @@
 #include <linux/icmpv6.h>
 #include <linux/mroute6.h>
 #include <linux/slab.h>
+#include <linux/indirect_call_wrapper.h>
 
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv6.h>
@@ -316,6 +317,9 @@ void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
 	ip6_sublist_rcv(&sublist, curr_dev, curr_net);
 }
 
+INDIRECT_CALLABLE_DECLARE(int udpv6_rcv(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *));
+
 /*
  *	Deliver the packet to the host
  */
@@ -391,7 +395,8 @@ void ip6_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int nexthdr,
 		    !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 			goto discard;
 
-		ret = ipprot->handler(skb);
+		ret = INDIRECT_CALL_2(ipprot->handler, tcp_v6_rcv, udpv6_rcv,
+				      skb);
 		if (ret > 0) {
 			if (ipprot->flags & INET6_PROTO_FINAL) {
 				/* Not an extension header, most likely UDP
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 82018bdce863..d58bf84e0f9a 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -43,6 +43,7 @@
 #include <linux/ipv6.h>
 #include <linux/icmpv6.h>
 #include <linux/random.h>
+#include <linux/indirect_call_wrapper.h>
 
 #include <net/tcp.h>
 #include <net/ndisc.h>
@@ -1435,7 +1436,7 @@ static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
 			skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
 }
 
-static int tcp_v6_rcv(struct sk_buff *skb)
+INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 {
 	struct sk_buff *skb_to_free;
 	int sdif = inet6_sdif(skb);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 2464fba569b4..b3fcafaf5576 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -36,6 +36,7 @@
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/indirect_call_wrapper.h>
 
 #include <net/addrconf.h>
 #include <net/ndisc.h>
@@ -1021,7 +1022,7 @@ static void udp_v6_early_demux(struct sk_buff *skb)
 	}
 }
 
-static __inline__ int udpv6_rcv(struct sk_buff *skb)
+INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
 {
 	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
 }
-- 
2.20.1

[PATCH net-next 3/4] net: use indirect calls helpers at early demux stage

[Paolo Abeni]

So that we avoid another indirect call per RX packet, if
early demux is enabled.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/ipv4/ip_input.c  | 5 ++++-
 net/ipv6/ip6_input.c | 5 ++++-
 net/ipv6/tcp_ipv6.c  | 2 +-
 net/ipv6/udp.c       | 2 +-
 4 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 8d78de4b0304..ed97724c5e33 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -309,6 +309,8 @@ static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev)
 	return true;
 }
 
+INDIRECT_CALLABLE_DECLARE(int udp_v4_early_demux(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int tcp_v4_early_demux(struct sk_buff *));
 static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 			      struct sk_buff *skb, struct net_device *dev)
 {
@@ -326,7 +328,8 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
 
 		ipprot = rcu_dereference(inet_protos[protocol]);
 		if (ipprot && (edemux = READ_ONCE(ipprot->early_demux))) {
-			err = edemux(skb);
+			err = INDIRECT_CALL_2(edemux, tcp_v4_early_demux,
+					      udp_v4_early_demux, skb);
 			if (unlikely(err))
 				goto drop_error;
 			/* must reload iph, skb->head might have changed */
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index adf06159837f..b50b1af1f530 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -48,6 +48,8 @@
 #include <net/inet_ecn.h>
 #include <net/dst_metadata.h>
 
+INDIRECT_CALLABLE_DECLARE(void udp_v6_early_demux(struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(void tcp_v6_early_demux(struct sk_buff *));
 static void ip6_rcv_finish_core(struct net *net, struct sock *sk,
 				struct sk_buff *skb)
 {
@@ -58,7 +60,8 @@ static void ip6_rcv_finish_core(struct net *net, struct sock *sk,
 
 		ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
 		if (ipprot && (edemux = READ_ONCE(ipprot->early_demux)))
-			edemux(skb);
+			INDIRECT_CALL_2(edemux, tcp_v6_early_demux,
+					udp_v6_early_demux, skb);
 	}
 	if (!skb_valid_dst(skb))
 		ip6_route_input(skb);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d58bf84e0f9a..beaf28456301 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1655,7 +1655,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
 	goto discard_it;
 }
 
-static void tcp_v6_early_demux(struct sk_buff *skb)
+INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
 {
 	const struct ipv6hdr *hdr;
 	const struct tcphdr *th;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index b3fcafaf5576..07fa579dfb96 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -981,7 +981,7 @@ static struct sock *__udp6_lib_demux_lookup(struct net *net,
 	return NULL;
 }
 
-static void udp_v6_early_demux(struct sk_buff *skb)
+INDIRECT_CALLABLE_SCOPE void udp_v6_early_demux(struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
 	const struct udphdr *uh;
-- 
2.20.1

[PATCH net-next 4/4] net: use indirect calls helpers at the socket layer

[Paolo Abeni]

This avoids an indirect call per {send,recv}msg syscall in
the common (IPv6 or IPv4 socket) case.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/socket.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index a180e1a9ff23..472fbefa5d9b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -90,6 +90,7 @@
 #include <linux/slab.h>
 #include <linux/xattr.h>
 #include <linux/nospec.h>
+#include <linux/indirect_call_wrapper.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -108,6 +109,13 @@
 #include <net/busy_poll.h>
 #include <linux/errqueue.h>
 
+/* proto_ops for ipv4 and ipv6 use the same {recv,send}msg function */
+#if IS_ENABLED(CONFIG_INET)
+#define INDIRECT_CALL_INET4(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
+#else
+#define INDIRECT_CALL_INET4(f, f1, ...) f(__VA_ARGS__)
+#endif
+
 #ifdef CONFIG_NET_RX_BUSY_POLL
 unsigned int sysctl_net_busy_read __read_mostly;
 unsigned int sysctl_net_busy_poll __read_mostly;
@@ -645,10 +653,12 @@ EXPORT_SYMBOL(__sock_tx_timestamp);
  *	Sends @msg through @sock, passing through LSM.
  *	Returns the number of bytes sent, or an error code.
  */
-
+INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
+					   size_t));
 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
 {
-	int ret = sock->ops->sendmsg(sock, msg, msg_data_left(msg));
+	int ret = INDIRECT_CALL_INET4(sock->ops->sendmsg, inet_sendmsg, sock,
+				      msg, msg_data_left(msg));
 	BUG_ON(ret == -EIOCBQUEUED);
 	return ret;
 }
@@ -874,11 +884,13 @@ EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
  *	Receives @msg from @sock, passing through LSM. Returns the total number
  *	of bytes received, or an error.
  */
-
+INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
+					   size_t , int ));
 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
 				     int flags)
 {
-	return sock->ops->recvmsg(sock, msg, msg_data_left(msg), flags);
+	return INDIRECT_CALL_INET4(sock->ops->recvmsg, inet_recvmsg, sock, msg,
+				   msg_data_left(msg), flags);
 }
 
 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
-- 
2.20.1

Re: [PATCH net-next 0/4] net: extend indirect calls helper usage

[David Miller]

From: Paolo Abeni <pabeni@redhat.com>
Date: Fri,  3 May 2019 17:01:35 +0200

> This series applies the indirect calls helper introduced with commit 
> 283c16a2dfd3 ("indirect call wrappers: helpers to speed-up indirect 
> calls of builtin") to more hooks inside the network stack.
> 
> Overall this avoids up to 4 indirect calls for each RX packets,
> giving small but measurable gain TCP_RR workloads and 5% under UDP
> flood.

Series applied, thanks Paolo.