From nobody Fri Apr 3 00:56:16 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04E3AC6FA82 for ; Tue, 20 Sep 2022 02:54:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229669AbiITCyS (ORCPT ); Mon, 19 Sep 2022 22:54:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229580AbiITCyK (ORCPT ); Mon, 19 Sep 2022 22:54:10 -0400 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A288F54652; Mon, 19 Sep 2022 19:54:08 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=guwen@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0VQGxTZu_1663642435; Received: from localhost(mailfrom:guwen@linux.alibaba.com fp:SMTPD_---0VQGxTZu_1663642435) by smtp.aliyun-inc.com; Tue, 20 Sep 2022 10:54:06 +0800 From: Wen Gu To: kgraul@linux.ibm.com, wenjia@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next 1/2] net/smc: Introduce a specific sysctl for TEST_LINK time Date: Tue, 20 Sep 2022 10:53:54 +0800 Message-Id: <1663642434-30035-1-git-send-email-guwen@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1663641907-15852-1-git-send-email-guwen@linux.alibaba.com> References: <1663641907-15852-1-git-send-email-guwen@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Tony Lu --- 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/networ= king/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 buffer= s 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, str= uct 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 =3D READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); + lgr->llc_testlink_time =3D READ_ONCE(net->smc.sysctl_smcr_testlink_time) = * HZ; } =20 /* 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 @@ =20 #define SMC_LLC_WAIT_FIRST_TIME (5 * HZ) #define SMC_LLC_WAIT_TIME (2 * HZ) +#define SMC_LLC_TESTLINK_DEFAULT_TIME 30 =20 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 @@ =20 #include "smc.h" #include "smc_core.h" +#include "smc_llc.h" #include "smc_sysctl.h" =20 +static int smcr_testlink_time_min =3D 1; +static int smcr_testlink_time_max =3D (INT_MAX / HZ); + static struct ctl_table smc_table[] =3D { { .procname =3D "autocorking_size", @@ -35,6 +39,15 @@ .extra1 =3D SYSCTL_ZERO, .extra2 =3D SYSCTL_TWO, }, + { + .procname =3D "smcr_testlink_time", + .data =3D &init_net.smc.sysctl_smcr_testlink_time, + .maxlen =3D sizeof(int), + .mode =3D 0644, + .proc_handler =3D proc_dointvec_minmax, + .extra1 =3D &smcr_testlink_time_min, + .extra2 =3D &smcr_testlink_time_max, + }, { } }; =20 @@ -60,6 +73,7 @@ int __net_init smc_sysctl_net_init(struct net *net) =20 net->smc.sysctl_autocorking_size =3D SMC_AUTOCORKING_DEFAULT_SIZE; net->smc.sysctl_smcr_buf_type =3D SMCR_PHYS_CONT_BUFS; + net->smc.sysctl_smcr_testlink_time =3D SMC_LLC_TESTLINK_DEFAULT_TIME; =20 return 0; =20 --=20 1.8.3.1