[RFC PATCH net-next 1/4] txhash: Make rethinking txhash behavior configurable via sysctl
From: Akhmat Karakotov <hidden>
Date: 2021-10-25 20:37:42
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
Add a per ns sysctl that controls the txhash rethink behavior, sk_rethink_txhash. When enabled, the same behavior is retained, when disabled, rethink is not performed. Sysctl is disabled by default. Signed-off-by: Akhmat Karakotov <redacted> --- include/net/netns/core.h | 2 ++ include/net/sock.h | 34 +++++++++++++++++++++------------- include/uapi/linux/socket.h | 3 +++ net/core/net_namespace.c | 3 +++ net/core/sysctl_net_core.c | 7 +++++++ 5 files changed, 36 insertions(+), 13 deletions(-)
diff --git a/include/net/netns/core.h b/include/net/netns/core.h
index 36c2d998a43c..177980b46ed7 100644
--- a/include/net/netns/core.h
+++ b/include/net/netns/core.h@@ -11,6 +11,8 @@ struct netns_core { int sysctl_somaxconn; + unsigned int sysctl_txrehash; + #ifdef CONFIG_PROC_FS int __percpu *sock_inuse; struct prot_inuse __percpu *prot_inuse;
diff --git a/include/net/sock.h b/include/net/sock.h
index 66a9a90f9558..d8a73edb1629 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -577,6 +577,18 @@ static inline bool sk_user_data_is_nocopy(const struct sock *sk) __tmp | SK_USER_DATA_NOCOPY); \ }) +static inline +struct net *sock_net(const struct sock *sk) +{ + return read_pnet(&sk->sk_net); +} + +static inline +void sock_net_set(struct sock *sk, struct net *net) +{ + write_pnet(&sk->sk_net, net); +} + /* * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK * or not whether his port will be reused by someone else. SK_FORCE_REUSE
@@ -1942,10 +1954,18 @@ static inline void sk_set_txhash(struct sock *sk) static inline bool sk_rethink_txhash(struct sock *sk) { - if (sk->sk_txhash) { + unsigned int rehash; + + if (!sk->sk_txhash) + return false; + + rehash = READ_ONCE(sock_net(sk)->core.sysctl_txrehash); + + if (rehash) { sk_set_txhash(sk); return true; } + return false; }
@@ -2596,18 +2616,6 @@ static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb) __kfree_skb(skb); } -static inline -struct net *sock_net(const struct sock *sk) -{ - return read_pnet(&sk->sk_net); -} - -static inline -void sock_net_set(struct sock *sk, struct net *net) -{ - write_pnet(&sk->sk_net, net); -} - static inline bool skb_sk_is_prefetched(struct sk_buff *skb) {
diff --git a/include/uapi/linux/socket.h b/include/uapi/linux/socket.h
index eb0a9a5b6e71..0accd6102ece 100644
--- a/include/uapi/linux/socket.h
+++ b/include/uapi/linux/socket.h@@ -31,4 +31,7 @@ struct __kernel_sockaddr_storage { #define SOCK_BUF_LOCK_MASK (SOCK_SNDBUF_LOCK | SOCK_RCVBUF_LOCK) +#define SOCK_TXREHASH_DISABLED 0 +#define SOCK_TXREHASH_ENABLED 1 + #endif /* _UAPI_LINUX_SOCKET_H */
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index a448a9b5bb2d..0d833b861f00 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c@@ -359,6 +359,9 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) static int __net_init net_defaults_init_net(struct net *net) { net->core.sysctl_somaxconn = SOMAXCONN; + + net->core.sysctl_txrehash = SOCK_TXREHASH_DISABLED; + return 0; }
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index c8496c1142c9..34144abbb6a0 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c@@ -592,6 +592,13 @@ static struct ctl_table netns_core_table[] = { .extra1 = SYSCTL_ZERO, .proc_handler = proc_dointvec_minmax }, + { + .procname = "txrehash", + .data = &init_net.core.sysctl_txrehash, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec + }, { } };
--
2.17.1