From patchwork Thu Oct 26 17:17:48 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirsher, Jeffrey T" X-Patchwork-Id: 830831 X-Patchwork-Delegate: shemminger@vyatta.com Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3yNDHP2Rw4z9t2c for ; Fri, 27 Oct 2017 04:18:25 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932458AbdJZRSN (ORCPT ); Thu, 26 Oct 2017 13:18:13 -0400 Received: from mga11.intel.com ([192.55.52.93]:35393 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932447AbdJZRSK (ORCPT ); Thu, 26 Oct 2017 13:18:10 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Oct 2017 10:18:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,301,1505804400"; d="scan'208";a="1891506" Received: from jtkirshe-desk.jf.intel.com (HELO jtkirshe-DESK.amr.corp.intel.com.com) ([134.134.177.54]) by orsmga002.jf.intel.com with ESMTP; 26 Oct 2017 10:18:09 -0700 From: Jeff Kirsher To: davem@davemloft.net Cc: Vinicius Costa Gomes , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, jogreene@redhat.com, Jeff Kirsher Subject: [iproute2 1/2] tc: Add support for the CBS qdisc Date: Thu, 26 Oct 2017 10:17:48 -0700 Message-Id: <20171026171749.45134-2-jeffrey.t.kirsher@intel.com> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171026171749.45134-1-jeffrey.t.kirsher@intel.com> References: <20171026171749.45134-1-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Vinicius Costa Gomes The Credit Based Shaper (CBS) queueing discipline allows bandwidth reservation with sub-milisecond precision. It is defined by the 802.1Q-2014 specification (section 8.6.8.2 and Annex L). The syntax is: tc qdisc add dev DEV parent NODE cbs locredit hicredit sendslope idleslope (The order is not important) Signed-off-by: Vinicius Costa Gomes Signed-off-by: Jeff Kirsher --- tc/Makefile | 1 + tc/q_cbs.c | 142 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 143 insertions(+) create mode 100644 tc/q_cbs.c diff --git a/tc/Makefile b/tc/Makefile index 777de5e6..24bd3e2e 100644 --- a/tc/Makefile +++ b/tc/Makefile @@ -69,6 +69,7 @@ TCMODULES += q_hhf.o TCMODULES += q_clsact.o TCMODULES += e_bpf.o TCMODULES += f_matchall.o +TCMODULES += q_cbs.o TCSO := ifeq ($(TC_CONFIG_ATM),y) diff --git a/tc/q_cbs.c b/tc/q_cbs.c new file mode 100644 index 00000000..e53be654 --- /dev/null +++ b/tc/q_cbs.c @@ -0,0 +1,142 @@ +/* + * q_cbs.c CBS. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Vinicius Costa Gomes + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "utils.h" +#include "tc_util.h" + +static void explain(void) +{ + fprintf(stderr, "Usage: ... cbs hicredit BYTES locredit BYTES sendslope BPS idleslope BPS\n"); + fprintf(stderr, " [offload 0|1]\n"); + +} + +static void explain1(const char *arg, const char *val) +{ + fprintf(stderr, "cbs: illegal value for \"%s\": \"%s\"\n", arg, val); +} + +static int cbs_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n) +{ + struct tc_cbs_qopt opt = {}; + struct rtattr *tail; + + while (argc > 0) { + if (matches(*argv, "offload") == 0) { + NEXT_ARG(); + if (opt.offload) { + fprintf(stderr, "cbs: duplicate \"offload\" specification\n"); + return -1; + } + if (get_u8(&opt.offload, *argv, 0)) { + explain1("offload", *argv); + return -1; + } + } else if (matches(*argv, "hicredit") == 0) { + NEXT_ARG(); + if (opt.hicredit) { + fprintf(stderr, "cbs: duplicate \"hicredit\" specification\n"); + return -1; + } + if (get_s32(&opt.hicredit, *argv, 0)) { + explain1("hicredit", *argv); + return -1; + } + } else if (matches(*argv, "locredit") == 0) { + NEXT_ARG(); + if (opt.locredit) { + fprintf(stderr, "cbs: duplicate \"locredit\" specification\n"); + return -1; + } + if (get_s32(&opt.locredit, *argv, 0)) { + explain1("locredit", *argv); + return -1; + } + } else if (matches(*argv, "sendslope") == 0) { + NEXT_ARG(); + if (opt.sendslope) { + fprintf(stderr, "cbs: duplicate \"sendslope\" specification\n"); + return -1; + } + if (get_s32(&opt.sendslope, *argv, 0)) { + explain1("sendslope", *argv); + return -1; + } + } else if (matches(*argv, "idleslope") == 0) { + NEXT_ARG(); + if (opt.idleslope) { + fprintf(stderr, "cbs: duplicate \"idleslope\" specification\n"); + return -1; + } + if (get_s32(&opt.idleslope, *argv, 0)) { + explain1("idleslope", *argv); + return -1; + } + } else if (strcmp(*argv, "help") == 0) { + explain(); + return -1; + } else { + fprintf(stderr, "cbs: unknown parameter \"%s\"\n", *argv); + explain(); + return -1; + } + argc--; argv++; + } + + tail = NLMSG_TAIL(n); + addattr_l(n, 1024, TCA_OPTIONS, NULL, 0); + addattr_l(n, 2024, TCA_CBS_PARMS, &opt, sizeof(opt)); + tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail; + return 0; +} + +static int cbs_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) +{ + struct rtattr *tb[TCA_CBS_MAX+1]; + struct tc_cbs_qopt *qopt; + + if (opt == NULL) + return 0; + + parse_rtattr_nested(tb, TCA_CBS_MAX, opt); + + if (tb[TCA_CBS_PARMS] == NULL) + return -1; + + qopt = RTA_DATA(tb[TCA_CBS_PARMS]); + if (RTA_PAYLOAD(tb[TCA_CBS_PARMS]) < sizeof(*qopt)) + return -1; + + fprintf(f, "hicredit %d ", qopt->hicredit); + fprintf(f, "locredit %d ", qopt->locredit); + fprintf(f, "sendslope %d ", qopt->sendslope); + fprintf(f, "idleslope %d ", qopt->idleslope); + fprintf(f, "offload %d ", qopt->offload); + + return 0; +} + +struct qdisc_util cbs_qdisc_util = { + .id = "cbs", + .parse_qopt = cbs_parse_opt, + .print_qopt = cbs_print_opt, +}; From patchwork Thu Oct 26 17:17:49 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirsher, Jeffrey T" X-Patchwork-Id: 830829 X-Patchwork-Delegate: shemminger@vyatta.com Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3yNDHF0p9Bz9t66 for ; Fri, 27 Oct 2017 04:18:17 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932466AbdJZRSP (ORCPT ); Thu, 26 Oct 2017 13:18:15 -0400 Received: from mga11.intel.com ([192.55.52.93]:35393 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932449AbdJZRSL (ORCPT ); Thu, 26 Oct 2017 13:18:11 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Oct 2017 10:18:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,301,1505804400"; d="scan'208";a="1891508" Received: from jtkirshe-desk.jf.intel.com (HELO jtkirshe-DESK.amr.corp.intel.com.com) ([134.134.177.54]) by orsmga002.jf.intel.com with ESMTP; 26 Oct 2017 10:18:09 -0700 From: Jeff Kirsher To: davem@davemloft.net Cc: Vinicius Costa Gomes , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, jogreene@redhat.com, Jeff Kirsher Subject: [iproute2 2/2] man: Add initial manpage for tc-cbs(8) Date: Thu, 26 Oct 2017 10:17:49 -0700 Message-Id: <20171026171749.45134-3-jeffrey.t.kirsher@intel.com> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171026171749.45134-1-jeffrey.t.kirsher@intel.com> References: <20171026171749.45134-1-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Vinicius Costa Gomes Signed-off-by: Vinicius Costa Gomes Signed-off-by: Jeff Kirsher --- man/man8/tc-cbs.8 | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 man/man8/tc-cbs.8 diff --git a/man/man8/tc-cbs.8 b/man/man8/tc-cbs.8 new file mode 100644 index 00000000..97e00c84 --- /dev/null +++ b/man/man8/tc-cbs.8 @@ -0,0 +1,112 @@ +.TH CBS 8 "18 Sept 2017" "iproute2" "Linux" +.SH NAME +CBS \- Credit Based Shaper (CBS) Qdisc +.SH SYNOPSIS +.B tc qdisc ... dev +dev +.B parent +classid +.B [ handle +major: +.B ] cbs idleslope +idleslope +.B sendslope +sendslope +.B hicredit +hicredit +.B locredit +locredit +.B [ offload +0|1 +.B ] + +.SH DESCRIPTION +The CBS (Credit Based Shaper) qdisc implements the shaping algorithm +defined by the IEEE 802.1Q-2014 Section 8.6.8.2, which applies a well +defined rate limiting method to the traffic. + +This queueing discipline is intended to be used by TSN (Time Sensitive +Networking) applications, the CBS parameters are derived directly by +what is described by the Annex L of the IEEE 802.1Q-2014 +Sepcification. The algorithm and how it affects the latency are +detailed there. + +CBS is meant to be installed under another qdisc that maps packet +flows to traffic classes, one example is +.BR mqprio(8). + +.SH PARAMETERS +.TP +idleslope +Idleslope is the rate of credits that is accumulated (in kilobits per +second) when there is at least one packet waiting for transmission. +Packets are transmitted when the current value of credits is equal or +greater than zero. When there is no packet to be transmitted the +amount of credits is set to zero. This is the main tunable of the CBS +algorithm. +.TP +sendslope +Sendslope is the rate of credits that is depleted (it should be a +negative number of kilobits per second) when a transmission is +ocurring. It can be calculated as follows, (IEEE 802.1Q-2014 Section +8.6.8.2 item g): + +sendslope = idleslope - port_transmit_rate + +.TP +hicredit +Hicredit defines the maximum amount of credits (in bytes) that can be +accumulated. Hicredit depends on the characteristics of interfering +traffic, 'max_interference_size' is the maximum size of any burst of +traffic that can delay the transmission of a frame that is available +for transmission for this traffic class, (IEEE 802.1Q-2014 Annex L, +Equation L-3): + +hicredit = max_interference_size * (idleslope / port_transmit_rate) + +.TP +locredit +Locredit is the minimum amount of credits that can be reached. It is a +function of the traffic flowing through this qdisc (IEEE 802.1Q-2014 +Annex L, Equation L-2): + +locredit = max_frame_size * (sendslope / port_transmit_rate) + +.TP +offload +When +.B offload +is 1, +.BR cbs(8) +will try to configure the network interface so the CBS algorithm runs +in the controller. The default is 0. + +.SH EXAMPLES + +CBS is used to enforce a Quality of Service by limiting the data rate +of a traffic class, to separate packets into traffic classes the user +may choose +.BR mqprio(8), +and configure it like this: + +.EX +# tc qdisc add dev eth0 handle 100: parent root mqprio num_tc 3 \\ + map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \\ + queues 1@0 1@1 2@2 \\ + hw 0 +.EE +.P +To replace the current queuing disciple by CBS in the current queueing +discipline connected to traffic class number 0, issue: +.P +.EX +# tc qdisc replace dev eth0 parent 100:4 cbs \\ + locredit -1470 hicredit 30 sendslope -980000 idleslope 20000 +.EE + +These values are obtained from the following parameters, idleslope is +20mbit/s, the transmission rate is 1Gbit/s and the maximum interfering +frame size is 1500 bytes. + +.SH AUTHORS +Vinicius Costa Gomes