[Bloat] [PATCH v12 iproute2] codel: Controlled Delay AQM

Eric Dumazet eric.dumazet at gmail.com
Wed May 9 06:54:19 PDT 2012


From: Eric Dumazet <edumazet at google.com>

An implementation of CoDel AQM, from Kathleen Nichols and Van Jacobson. 

 http://queue.acm.org/detail.cfm?id=2209336 

Based on initial work from Dave Taht.

tc qdisc ... codel [ limit PACKETS ] [ target TIME ]
                   [ interval TIME ] [ ecn ]

Signed-off-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: Dave Taht <dave.taht at bufferbloat.net>
Cc: Kathleen Nichols <nichols at pollere.com>
Cc: Van Jacobson <van at pollere.net>
---
This is the patch against iproute2

 include/linux/pkt_sched.h |   28 +++++
 tc/Makefile               |    1 
 tc/q_codel.c              |  189 ++++++++++++++++++++++++++++++++++++
 3 files changed, 218 insertions(+)

diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index 410b33d..4d542ed 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -654,4 +654,32 @@ struct tc_qfq_stats {
 	__u32 lmax;
 };
 
+/* CODEL */
+
+enum {
+	TCA_CODEL_UNSPEC,
+	TCA_CODEL_TARGET,
+	TCA_CODEL_LIMIT,
+	TCA_CODEL_INTERVAL,
+	TCA_CODEL_ECN,
+	__TCA_CODEL_MAX
+};
+
+#define TCA_CODEL_MAX	(__TCA_CODEL_MAX - 1)
+
+struct tc_codel_xstats {
+	__u32	maxpacket; /* largest packet we've seen so far */
+	__u32	count;
+	__u32	lastcount;
+	__u32	ldelay; /* in-queue delay seen by most recently dequeued packet */
+	__u32	drop_next;
+	__u32	drop_overlimit;
+	__u32	ecn_mark;
+	__u32	dropping;
+	__u32	state1;
+	__u32	state2;
+	__u32	state3;
+	__u32	states;
+};
+
 #endif
diff --git a/tc/Makefile b/tc/Makefile
index be8cd5a..8a7cc8d 100644
--- a/tc/Makefile
+++ b/tc/Makefile
@@ -47,6 +47,7 @@ TCMODULES += em_cmp.o
 TCMODULES += em_u32.o
 TCMODULES += em_meta.o
 TCMODULES += q_mqprio.o
+TCMODULES += q_codel.o
 
 TCSO :=
 ifeq ($(TC_CONFIG_ATM),y)
diff --git a/tc/q_codel.c b/tc/q_codel.c
new file mode 100644
index 0000000..485fe47
--- /dev/null
+++ b/tc/q_codel.c
@@ -0,0 +1,189 @@
+/*
+ * Codel - The Controlled-Delay Active Queue Management algorithm
+ *
+ *  Copyright (C) 2011-2012 Kathleen Nichols <nichols at pollere.com>
+ *  Copyright (C) 2011-2012 Van Jacobson <van at pollere.com>
+ *  Copyright (C) 2012 Michael D. Taht <dave.taht at bufferbloat.net>
+ *  Copyright (C) 2012 Eric Dumazet <edumazet at google.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+#include "utils.h"
+#include "tc_util.h"
+
+static void explain(void)
+{
+	fprintf(stderr, "Usage: ... codel [ limit PACKETS ] [ target TIME]\n");
+	fprintf(stderr, "                 [ interval TIME ] [ ecn ]\n");
+}
+
+static int codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
+			   struct nlmsghdr *n)
+{
+	unsigned limit = 0;
+	unsigned target = 0;
+	unsigned interval = 0;
+	int ecn = -1;
+	struct rtattr *tail;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "limit") == 0) {
+			NEXT_ARG();
+			if (get_unsigned(&limit, *argv, 0)) {
+				fprintf(stderr, "Illegal \"limit\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "target") == 0) {
+			NEXT_ARG();
+			if (get_time(&target, *argv)) {
+				fprintf(stderr, "Illegal \"target\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "interval") == 0) {
+			NEXT_ARG();
+			if (get_time(&interval, *argv)) {
+				fprintf(stderr, "Illegal \"interval\"\n");
+				return -1;
+			}
+		} else if (strcmp(*argv, "ecn") == 0) {
+			ecn = 1;
+		} else if (strcmp(*argv, "noecn") == 0) {
+			ecn = 0;
+		} else if (strcmp(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "What is \"%s\"?\n", *argv);
+			explain();
+			return -1;
+		}
+		argc--; argv++;
+	}
+
+	tail = NLMSG_TAIL(n);
+	addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
+	if (limit)
+		addattr_l(n, 1024, TCA_CODEL_LIMIT, &limit, sizeof(limit));
+	if (interval)
+		addattr_l(n, 1024, TCA_CODEL_INTERVAL, &interval, sizeof(interval));
+	if (target)
+		addattr_l(n, 1024, TCA_CODEL_TARGET, &target, sizeof(target));
+	if (ecn != -1)
+		addattr_l(n, 1024, TCA_CODEL_ECN, &ecn, sizeof(ecn));
+	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
+	return 0;
+}
+
+static int codel_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+	struct rtattr *tb[TCA_CODEL_MAX + 1];
+	unsigned limit;
+	unsigned interval;
+	unsigned target;
+	unsigned ecn;
+	SPRINT_BUF(b1);
+
+	if (opt == NULL)
+		return 0;
+
+	parse_rtattr_nested(tb, TCA_CODEL_MAX, opt);
+
+	if (tb[TCA_CODEL_ECN] &&
+	    RTA_PAYLOAD(tb[TCA_CODEL_ECN]) >= sizeof(__u32)) {
+		ecn = rta_getattr_u32(tb[TCA_CODEL_ECN]);
+		if (ecn)
+			fprintf(f, "ecn ");
+	}
+	if (tb[TCA_CODEL_LIMIT] &&
+	    RTA_PAYLOAD(tb[TCA_CODEL_LIMIT]) >= sizeof(__u32)) {
+		limit = rta_getattr_u32(tb[TCA_CODEL_LIMIT]);
+		fprintf(f, "limit %up ", limit);
+	}
+	if (tb[TCA_CODEL_TARGET] &&
+	    RTA_PAYLOAD(tb[TCA_CODEL_TARGET]) >= sizeof(__u32)) {
+		target = rta_getattr_u32(tb[TCA_CODEL_TARGET]);
+		fprintf(f, "target %s ", sprint_time(target, b1));
+	}
+	if (tb[TCA_CODEL_INTERVAL] &&
+	    RTA_PAYLOAD(tb[TCA_CODEL_INTERVAL]) >= sizeof(__u32)) {
+		interval = rta_getattr_u32(tb[TCA_CODEL_INTERVAL]);
+		fprintf(f, "interval %s ", sprint_time(interval, b1));
+	}
+
+	return 0;
+}
+
+static int codel_print_xstats(struct qdisc_util *qu, FILE *f,
+			      struct rtattr *xstats)
+{
+	struct tc_codel_xstats *st;
+	SPRINT_BUF(b1);
+
+	if (xstats == NULL)
+		return 0;
+
+	if (RTA_PAYLOAD(xstats) < sizeof(*st))
+		return -1;
+
+	st = RTA_DATA(xstats);
+	fprintf(f, "  maxpacket %u count %u lastcount %u ldelay %s",
+		st->maxpacket, st->count, st->lastcount,
+		sprint_time(st->ldelay, b1));
+	if (st->dropping)
+		fprintf(f, " dropping");
+	if (st->drop_next)
+		fprintf(f, " drop_next %s", sprint_time(st->drop_next, b1));
+	fprintf(f, "\n  ecn_mark %u", st->ecn_mark);
+	fprintf(f, " drop_overlimit %u", st->drop_overlimit); 
+	fprintf(f, " states %u : %u %u %u",
+		st->states, st->state1, st->state2, st->state3);
+	return 0;
+
+}
+
+struct qdisc_util codel_qdisc_util = {
+	.id		= "codel",
+	.parse_qopt	= codel_parse_opt,
+	.print_qopt	= codel_print_opt,
+	.print_xstats	= codel_print_xstats,
+};




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