On Tue, Sep 20, 2022 at 10:53:54AM +0800, Wen Gu wrote: >SMC-R tests the viability of link by sending out TEST_LINK LLC >messages over RoCE fabric when connections on link have been >idle for a time longer than keepalive interval (testlink time). > >But using tcp_keepalive_time as testlink time maybe not quite >suitable because it is default no less than two hours[1], which >is too long for single link to find peer dead. The active host >will still use peer-dead link (QP) sending messages, and can't >find out until get IB_WC_RETRY_EXC_ERR error CQEs, which takes >more time than TEST_LINK timeout (SMC_LLC_WAIT_TIME) normally. > >So this patch introduces a independent sysctl for SMC-R to set >link keepalive time, in order to detect link down in time. The >default value is 30 seconds. > >[1] https://www.rfc-editor.org/rfc/rfc1122#page-101 > >Signed-off-by: Wen Gu <guwen@xxxxxxxxxxxxxxxxx> >--- > Documentation/networking/smc-sysctl.rst | 7 +++++++ > include/net/netns/smc.h | 1 + > net/smc/smc_llc.c | 2 +- > net/smc/smc_llc.h | 1 + > net/smc/smc_sysctl.c | 14 ++++++++++++++ > 5 files changed, 24 insertions(+), 1 deletion(-) > >diff --git a/Documentation/networking/smc-sysctl.rst b/Documentation/networking/smc-sysctl.rst >index 742e90e..f8c3d59 100644 >--- a/Documentation/networking/smc-sysctl.rst >+++ b/Documentation/networking/smc-sysctl.rst >@@ -34,3 +34,10 @@ smcr_buf_type - INTEGER > - 1 - Use virtually contiguous buffers > - 2 - Mixed use of the two types. Try physically contiguous buffers first. > If not available, use virtually contiguous buffers then. >+ >+smcr_testlink_time - INTEGER >+ How frequently SMC-R link sends out TEST_LINK LLC messages to confirm >+ viability, after the last activity of connections on it. The maximum >+ value is (INT_MAX / HZ) seconds, the minimum value is 1 second. >+ >+ Default: 30 seconds. >diff --git a/include/net/netns/smc.h b/include/net/netns/smc.h >index 2adbe2b..d295e2c 100644 >--- a/include/net/netns/smc.h >+++ b/include/net/netns/smc.h >@@ -19,5 +19,6 @@ struct netns_smc { > #endif > unsigned int sysctl_autocorking_size; > unsigned int sysctl_smcr_buf_type; >+ int sysctl_smcr_testlink_time; > }; > #endif >diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c >index 175026a..388bd2e 100644 >--- a/net/smc/smc_llc.c >+++ b/net/smc/smc_llc.c >@@ -2127,7 +2127,7 @@ void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc) > init_waitqueue_head(&lgr->llc_flow_waiter); > init_waitqueue_head(&lgr->llc_msg_waiter); > mutex_init(&lgr->llc_conf_mutex); >- lgr->llc_testlink_time = READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); >+ lgr->llc_testlink_time = READ_ONCE(net->smc.sysctl_smcr_testlink_time) * HZ; > } > > /* called after lgr was removed from lgr_list */ >diff --git a/net/smc/smc_llc.h b/net/smc/smc_llc.h >index 4404e52..1de9a29 100644 >--- a/net/smc/smc_llc.h >+++ b/net/smc/smc_llc.h >@@ -19,6 +19,7 @@ > > #define SMC_LLC_WAIT_FIRST_TIME (5 * HZ) > #define SMC_LLC_WAIT_TIME (2 * HZ) >+#define SMC_LLC_TESTLINK_DEFAULT_TIME 30 I'm wondering why we don't follow the upper to macros using (30 * HZ) ? > > enum smc_llc_reqresp { > SMC_LLC_REQ, >diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c >index 0613868..7f68520 100644 >--- a/net/smc/smc_sysctl.c >+++ b/net/smc/smc_sysctl.c >@@ -16,8 +16,12 @@ > > #include "smc.h" > #include "smc_core.h" >+#include "smc_llc.h" > #include "smc_sysctl.h" > >+static int smcr_testlink_time_min = 1; >+static int smcr_testlink_time_max = (INT_MAX / HZ); >+ > static struct ctl_table smc_table[] = { > { > .procname = "autocorking_size", >@@ -35,6 +39,15 @@ > .extra1 = SYSCTL_ZERO, > .extra2 = SYSCTL_TWO, > }, >+ { >+ .procname = "smcr_testlink_time", >+ .data = &init_net.smc.sysctl_smcr_testlink_time, >+ .maxlen = sizeof(int), >+ .mode = 0644, >+ .proc_handler = proc_dointvec_minmax, >+ .extra1 = &smcr_testlink_time_min, >+ .extra2 = &smcr_testlink_time_max, >+ }, > { } > }; > >@@ -60,6 +73,7 @@ int __net_init smc_sysctl_net_init(struct net *net) > > net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE; > net->smc.sysctl_smcr_buf_type = SMCR_PHYS_CONT_BUFS; >+ net->smc.sysctl_smcr_testlink_time = SMC_LLC_TESTLINK_DEFAULT_TIME; > > return 0; > >-- >1.8.3.1
