[PATCH v5 net-next 4/4] net: add socket option for low latency polling
From: Eliezer Tamir <hidden>
Date: 2013-06-14 13:34:21
Also in:
lkml
Subsystem:
alpha port, generic include/asm header files, linux for powerpc (32-bit and 64-bit), mips, networking [general], networking [sockets], parisc architecture, s390 architecture, sparc + ultrasparc (sparc/sparc64), tensilica xtensa port (xtensa), the rest · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Arnd Bergmann, Madhavan Srinivasan, Thomas Bogendoerfer, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, "James E.J. Bottomley", Helge Deller, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Andreas Larsson, Chris Zankel, Max Filippov, Linus Torvalds
adds a socket option for low latency polling. This allows overriding the global sysctl value with a per-socket one. Unexport sysctl_net_ll_poll since for now it's not needed in modules. Signed-off-by: Eliezer Tamir <redacted> --- arch/alpha/include/uapi/asm/socket.h | 2 ++ arch/avr32/include/uapi/asm/socket.h | 2 ++ arch/cris/include/uapi/asm/socket.h | 2 ++ arch/frv/include/uapi/asm/socket.h | 2 ++ arch/h8300/include/uapi/asm/socket.h | 2 ++ arch/ia64/include/uapi/asm/socket.h | 2 ++ arch/m32r/include/uapi/asm/socket.h | 2 ++ arch/mips/include/uapi/asm/socket.h | 2 ++ arch/mn10300/include/uapi/asm/socket.h | 2 ++ arch/parisc/include/uapi/asm/socket.h | 2 ++ arch/powerpc/include/uapi/asm/socket.h | 2 ++ arch/s390/include/uapi/asm/socket.h | 2 ++ arch/sparc/include/uapi/asm/socket.h | 2 ++ arch/xtensa/include/uapi/asm/socket.h | 2 ++ include/net/ll_poll.h | 12 ++++++------ include/net/sock.h | 2 ++ include/uapi/asm-generic/socket.h | 2 ++ net/core/sock.c | 20 ++++++++++++++++++++ net/socket.c | 1 - 19 files changed, 58 insertions(+), 7 deletions(-)
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index eee6ea7..4885825 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h@@ -81,4 +81,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/avr32/include/uapi/asm/socket.h b/arch/avr32/include/uapi/asm/socket.h
index 37401f5..79b6179 100644
--- a/arch/avr32/include/uapi/asm/socket.h
+++ b/arch/avr32/include/uapi/asm/socket.h@@ -74,4 +74,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* __ASM_AVR32_SOCKET_H */
diff --git a/arch/cris/include/uapi/asm/socket.h b/arch/cris/include/uapi/asm/socket.h
index ba409c9..47b1ec5 100644
--- a/arch/cris/include/uapi/asm/socket.h
+++ b/arch/cris/include/uapi/asm/socket.h@@ -76,6 +76,8 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_SOCKET_H */
diff --git a/arch/frv/include/uapi/asm/socket.h b/arch/frv/include/uapi/asm/socket.h
index 31dbb5d..dbc0852 100644
--- a/arch/frv/include/uapi/asm/socket.h
+++ b/arch/frv/include/uapi/asm/socket.h@@ -74,5 +74,7 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_SOCKET_H */
diff --git a/arch/h8300/include/uapi/asm/socket.h b/arch/h8300/include/uapi/asm/socket.h
index 5d1c6d0..a38d38a 100644
--- a/arch/h8300/include/uapi/asm/socket.h
+++ b/arch/h8300/include/uapi/asm/socket.h@@ -74,4 +74,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_SOCKET_H */
diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h
index 6b4329f..d3358b7 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h@@ -83,4 +83,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h
index 2a3b59e..44aaf46 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h@@ -74,4 +74,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 3b21150..6a07992 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h@@ -92,4 +92,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/mn10300/include/uapi/asm/socket.h b/arch/mn10300/include/uapi/asm/socket.h
index b4ce844..db80fd3 100644
--- a/arch/mn10300/include/uapi/asm/socket.h
+++ b/arch/mn10300/include/uapi/asm/socket.h@@ -74,4 +74,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 70c512a..f866fff 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h@@ -73,6 +73,8 @@ #define SO_SELECT_ERR_QUEUE 0x4026 +#define SO_LL 0x4027 + /* O_NONBLOCK clashes with the bits used for socket types. Therefore we * have to define SOCK_NONBLOCK to a different value here. */
diff --git a/arch/powerpc/include/uapi/asm/socket.h b/arch/powerpc/include/uapi/asm/socket.h
index a36daf3..405fb09 100644
--- a/arch/powerpc/include/uapi/asm/socket.h
+++ b/arch/powerpc/include/uapi/asm/socket.h@@ -81,4 +81,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_POWERPC_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h
index 2dacb306..0c5105fb 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h@@ -80,4 +80,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 89f49b6..b46c3fa 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h@@ -70,6 +70,8 @@ #define SO_SELECT_ERR_QUEUE 0x0029 +#define SO_LL 0x0030 + /* Security levels - as per NRL IPv6 - don't actually do anything */ #define SO_SECURITY_AUTHENTICATION 0x5001 #define SO_SECURITY_ENCRYPTION_TRANSPORT 0x5002
diff --git a/arch/xtensa/include/uapi/asm/socket.h b/arch/xtensa/include/uapi/asm/socket.h
index a8f44f5..b21ace4 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h@@ -85,4 +85,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* _XTENSA_SOCKET_H */
diff --git a/include/net/ll_poll.h b/include/net/ll_poll.h
index 6930cbd..fcc7c36 100644
--- a/include/net/ll_poll.h
+++ b/include/net/ll_poll.h@@ -39,12 +39,12 @@ extern unsigned int sysctl_net_ll_poll __read_mostly; /* we can use sched_clock() because we don't care much about precision * we only care that the average is bounded */ -static inline u64 ll_end_time(void) +static inline u64 ll_end_time(struct sock *sk) { - u64 end_time = ACCESS_ONCE(sysctl_net_ll_poll); + u64 end_time = ACCESS_ONCE(sk->sk_ll_usec); /* we don't mind a ~2.5% imprecision - * sysctl_net_ll_poll is a u_int so this can't overflow + * sk->sk_ll_usec is a u_int so this can't overflow */ end_time = (end_time << 10) + sched_clock();
@@ -53,7 +53,7 @@ static inline u64 ll_end_time(void) static inline bool sk_valid_ll(struct sock *sk) { - return sysctl_net_ll_poll && sk->sk_napi_id && + return sk->sk_ll_usec && sk->sk_napi_id && !need_resched() && !signal_pending(current); }
@@ -65,7 +65,7 @@ static inline bool can_poll_ll(u64 end_time) static inline bool sk_poll_ll(struct sock *sk, int nonblock) { const struct net_device_ops *ops; - u64 end_time = ll_end_time(); + u64 end_time = ll_end_time(sk); struct napi_struct *napi; int rc = false;
@@ -118,7 +118,7 @@ static inline void sk_mark_ll(struct sock *sk, struct sk_buff *skb) #else /* CONFIG_NET_LL_RX_POLL */ -static inline u64 ll_end_time(void) +static inline u64 ll_end_time(struct sock *sk) { return 0; }
diff --git a/include/net/sock.h b/include/net/sock.h
index ac8e181..21db792 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -230,6 +230,7 @@ struct cg_proto; * @sk_wmem_queued: persistent queue size * @sk_forward_alloc: space allocated forward * @sk_napi_id: id of the last napi context to receive data for sk + * @sk_ll_usec: usecs to busypoll when there is no data * @sk_allocation: allocation mode * @sk_sndbuf: size of send buffer in bytes * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
@@ -328,6 +329,7 @@ struct sock { #endif #ifdef CONFIG_NET_LL_RX_POLL unsigned int sk_napi_id; + unsigned int sk_ll_usec; #endif atomic_t sk_drops; int sk_rcvbuf;
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index c5d2e3a..ca3a20d 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h@@ -76,4 +76,6 @@ #define SO_SELECT_ERR_QUEUE 45 +#define SO_LL 46 + #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/net/core/sock.c b/net/core/sock.c
index 788c0da..1e744b1 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c@@ -913,6 +913,19 @@ set_rcvbuf: sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool); break; +#ifdef CONFIG_NET_LL_RX_POLL + case SO_LL: + /* allow unprivileged users to decrease the value */ + if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN)) + ret = -EPERM; + else { + if (val < 0) + ret = -EINVAL; + else + sk->sk_ll_usec = val; + } + break; +#endif default: ret = -ENOPROTOOPT; break;
@@ -1170,6 +1183,12 @@ int sock_getsockopt(struct socket *sock, int level, int optname, v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE); break; +#ifdef CONFIG_NET_LL_RX_POLL + case SO_LL: + v.val = sk->sk_ll_usec; + break; +#endif + default: return -ENOPROTOOPT; }
@@ -2288,6 +2307,7 @@ void sock_init_data(struct socket *sock, struct sock *sk) #ifdef CONFIG_NET_LL_RX_POLL sk->sk_napi_id = 0; + sk->sk_ll_usec = sysctl_net_ll_poll; #endif /*
diff --git a/net/socket.c b/net/socket.c
index caaffa1..3eec3f7 100644
--- a/net/socket.c
+++ b/net/socket.c@@ -108,7 +108,6 @@ #ifdef CONFIG_NET_LL_RX_POLL unsigned int sysctl_net_ll_poll __read_mostly; -EXPORT_SYMBOL_GPL(sysctl_net_ll_poll); #endif static int sock_no_open(struct inode *irrelevant, struct file *dontcare);