From 12bbb0d163a90d81a2677cf7808d364697290207 Mon Sep 17 00:00:00 2001 From: Dust Li Date: Tue, 1 Mar 2022 17:43:58 +0800 Subject: [PATCH] net/smc: add sysctl for autocorking This add a new sysctl: net.smc.autocorking_size We can dynamically change the behaviour of autocorking by change the value of autocorking_size. Setting to 0 disables autocorking in SMC Signed-off-by: Dust Li Signed-off-by: David S. Miller --- Documentation/networking/smc-sysctl.rst | 23 +++++++++++++++++++++++ include/net/netns/smc.h | 1 + net/smc/smc_sysctl.c | 10 ++++++++++ net/smc/smc_tx.c | 2 +- 4 files changed, 35 insertions(+), 1 deletion(-) create mode 100644 Documentation/networking/smc-sysctl.rst diff --git a/Documentation/networking/smc-sysctl.rst b/Documentation/networking/smc-sysctl.rst new file mode 100644 index 0000000..c53f8c6 --- /dev/null +++ b/Documentation/networking/smc-sysctl.rst @@ -0,0 +1,23 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========= +SMC Sysctl +========= + +/proc/sys/net/smc/* Variables +============================== + +autocorking_size - INTEGER + Setting SMC auto corking size: + SMC auto corking is like TCP auto corking from the application's + perspective of view. When applications do consecutive small + write()/sendmsg() system calls, we try to coalesce these small writes + as much as possible, to lower total amount of CDC and RDMA Write been + sent. + autocorking_size limits the maximum corked bytes that can be sent to + the under device in 1 single sending. If set to 0, the SMC auto corking + is disabled. + Applications can still use TCP_CORK for optimal behavior when they + know how/when to uncork their sockets. + + Default: 64K diff --git a/include/net/netns/smc.h b/include/net/netns/smc.h index 1682eae..e5389ee 100644 --- a/include/net/netns/smc.h +++ b/include/net/netns/smc.h @@ -17,5 +17,6 @@ struct netns_smc { #ifdef CONFIG_SYSCTL struct ctl_table_header *smc_hdr; #endif + unsigned int sysctl_autocorking_size; }; #endif diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c index 8a3a8e1..3b59876 100644 --- a/net/smc/smc_sysctl.c +++ b/net/smc/smc_sysctl.c @@ -14,9 +14,17 @@ #include #include +#include "smc.h" #include "smc_sysctl.h" static struct ctl_table smc_table[] = { + { + .procname = "autocorking_size", + .data = &init_net.smc.sysctl_autocorking_size, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_douintvec, + }, { } }; @@ -40,6 +48,8 @@ static __net_init int smc_sysctl_init_net(struct net *net) if (!net->smc.smc_hdr) goto err_reg; + net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE; + return 0; err_reg: diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 062c6b1..257dc0d 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -147,7 +147,7 @@ static bool smc_should_autocork(struct smc_sock *smc) struct smc_connection *conn = &smc->conn; int corking_size; - corking_size = min(SMC_AUTOCORKING_DEFAULT_SIZE, + corking_size = min(sock_net(&smc->sk)->smc.sysctl_autocorking_size, conn->sndbuf_desc->len >> 1); if (atomic_read(&conn->cdc_pend_tx_wr) == 0 || -- 2.7.4