codel: add ce_threshold support to codel & fc_codel

codel & fq_codel packet schedulers are now able to have a threshold
for CE marking packets, regardless of the drop/nodrop decision taken by
CoDel.

This is particularly useful for dctcp and variants, that do not use
traditional ECN.

Note that fq_codel users would have to specify noecn if ce_threshold is
used, otherwise results would be not very interesting, as ecn is default
on for fq_codel.

$ tc -s qdisc show dev eth1
qdisc codel 8002: root refcnt 45 limit 1000p target 5.0ms ce_threshold
1.0ms interval 100.0ms
 Sent 4908469888317 bytes 3351813967 pkt (dropped 0, overlimits 0
requeues 21624365)
 rate 37671Mbit 3231836pps backlog 4904740b 250p requeues 21624365
  count 0 lastcount 0 ldelay 1.1ms drop_next 0us
  maxpacket 68130 ecn_mark 0 drop_overlimit 0 ce_mark 410861803

Signed-off-by: Eric Dumazet <edumazet@google.com>

diff --git a/tc/q_codel.c b/tc/q_codel.c
index dc4b3f6c5e6b209d4f1607c0adcc264af49f0238..c24246c5cf7f1752c143dc112bbc4550cbb92e55 100644 (file)
--- a/tc/q_codel.c
+++ b/tc/q_codel.c
@@ -4,7 +4,7 @@
  *  Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com>
  *  Copyright (C) 2011-2012 Van Jacobson <van@pollere.com>
  *  Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net>
- *  Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
+ *  Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -55,6 +55,7 @@ static void explain(void)
 {
        fprintf(stderr, "Usage: ... codel [ limit PACKETS ] [ target TIME]\n");
        fprintf(stderr, "                 [ interval TIME ] [ ecn | noecn ]\n");
+       fprintf(stderr, "                 [ ce_threshold TIME ]\n");
 }
 
 static int codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
@@ -63,6 +64,7 @@ static int codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
        unsigned limit = 0;
        unsigned target = 0;
        unsigned interval = 0;
+       unsigned ce_threshold = ~0U;
        int ecn = -1;
        struct rtattr *tail;
 
@@ -79,6 +81,12 @@ static int codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                                fprintf(stderr, "Illegal \"target\"\n");
                                return -1;
                        }
+               } else if (strcmp(*argv, "ce_threshold") == 0) {
+                       NEXT_ARG();
+                       if (get_time(&ce_threshold, *argv)) {
+                               fprintf(stderr, "Illegal \"ce_threshold\"\n");
+                               return -1;
+                       }
                } else if (strcmp(*argv, "interval") == 0) {
                        NEXT_ARG();
                        if (get_time(&interval, *argv)) {
@@ -110,6 +118,10 @@ static int codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                addattr_l(n, 1024, TCA_CODEL_TARGET, &target, sizeof(target));
        if (ecn != -1)
                addattr_l(n, 1024, TCA_CODEL_ECN, &ecn, sizeof(ecn));
+       if (ce_threshold != ~0U)
+               addattr_l(n, 1024, TCA_CODEL_CE_THRESHOLD,
+                         &ce_threshold, sizeof(ce_threshold));
+
        tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
        return 0;
 }
@@ -121,6 +133,7 @@ static int codel_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
        unsigned interval;
        unsigned target;
        unsigned ecn;
+       unsigned ce_threshold;
        SPRINT_BUF(b1);
 
        if (opt == NULL)
@@ -138,6 +151,11 @@ static int codel_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
                target = rta_getattr_u32(tb[TCA_CODEL_TARGET]);
                fprintf(f, "target %s ", sprint_time(target, b1));
        }
+       if (tb[TCA_CODEL_CE_THRESHOLD] &&
+           RTA_PAYLOAD(tb[TCA_CODEL_CE_THRESHOLD]) >= sizeof(__u32)) {
+               ce_threshold = rta_getattr_u32(tb[TCA_CODEL_CE_THRESHOLD]);
+               fprintf(f, "ce_threshold %s ", sprint_time(ce_threshold, b1));
+       }
        if (tb[TCA_CODEL_INTERVAL] &&
            RTA_PAYLOAD(tb[TCA_CODEL_INTERVAL]) >= sizeof(__u32)) {
                interval = rta_getattr_u32(tb[TCA_CODEL_INTERVAL]);
@@ -156,16 +174,19 @@ static int codel_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 static int codel_print_xstats(struct qdisc_util *qu, FILE *f,
                              struct rtattr *xstats)
 {
-       struct tc_codel_xstats *st;
+       struct tc_codel_xstats _st, *st;
        SPRINT_BUF(b1);
 
        if (xstats == NULL)
                return 0;
 
-       if (RTA_PAYLOAD(xstats) < sizeof(*st))
-               return -1;
-
        st = RTA_DATA(xstats);
+       if (RTA_PAYLOAD(xstats) < sizeof(*st)) {
+               memset(&_st, 0, sizeof(_st));
+               memcpy(&_st, st, RTA_PAYLOAD(xstats));
+               st = &_st;
+       }
+
        fprintf(f, "  count %u lastcount %u ldelay %s",
                st->count, st->lastcount, sprint_time(st->ldelay, b1));
        if (st->dropping)
@@ -176,6 +197,8 @@ static int codel_print_xstats(struct qdisc_util *qu, FILE *f,
                fprintf(f, " drop_next %s", sprint_time(st->drop_next, b1));
        fprintf(f, "\n  maxpacket %u ecn_mark %u drop_overlimit %u",
                st->maxpacket, st->ecn_mark, st->drop_overlimit);
+       if (st->ce_mark)
+               fprintf(f, " ce_mark %u", st->ce_mark);
        return 0;
 
 }

diff --git a/tc/q_fq_codel.c b/tc/q_fq_codel.c
index 1d3bfa2ac8e307f0fb614ff6f42656436b2392f3..4f747ebdff177482e3d389c73ae2051191d74164 100644 (file)
--- a/tc/q_fq_codel.c
+++ b/tc/q_fq_codel.c
@@ -1,7 +1,7 @@
 /*
  * Fair Queue Codel
  *
- *  Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
+ *  Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -53,6 +53,7 @@ static void explain(void)
        fprintf(stderr, "Usage: ... fq_codel [ limit PACKETS ] [ flows NUMBER ]\n");
        fprintf(stderr, "                    [ target TIME] [ interval TIME ]\n");
        fprintf(stderr, "                    [ quantum BYTES ] [ [no]ecn ]\n");
+       fprintf(stderr, "                    [ ce_threshold TIME ]\n");
 }
 
 static int fq_codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
@@ -63,6 +64,7 @@ static int fq_codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
        unsigned target = 0;
        unsigned interval = 0;
        unsigned quantum = 0;
+       unsigned ce_threshold = ~0U;
        int ecn = -1;
        struct rtattr *tail;
 
@@ -91,6 +93,12 @@ static int fq_codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                                fprintf(stderr, "Illegal \"target\"\n");
                                return -1;
                        }
+               } else if (strcmp(*argv, "ce_threshold") == 0) {
+                       NEXT_ARG();
+                       if (get_time(&ce_threshold, *argv)) {
+                               fprintf(stderr, "Illegal \"ce_threshold\"\n");
+                               return -1;
+                       }
                } else if (strcmp(*argv, "interval") == 0) {
                        NEXT_ARG();
                        if (get_time(&interval, *argv)) {
@@ -126,6 +134,9 @@ static int fq_codel_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                addattr_l(n, 1024, TCA_FQ_CODEL_TARGET, &target, sizeof(target));
        if (ecn != -1)
                addattr_l(n, 1024, TCA_FQ_CODEL_ECN, &ecn, sizeof(ecn));
+       if (ce_threshold != ~0U)
+               addattr_l(n, 1024, TCA_FQ_CODEL_CE_THRESHOLD,
+                         &ce_threshold, sizeof(ce_threshold));
        tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
        return 0;
 }
@@ -139,6 +150,7 @@ static int fq_codel_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt
        unsigned target;
        unsigned ecn;
        unsigned quantum;
+       unsigned ce_threshold;
        SPRINT_BUF(b1);
 
        if (opt == NULL)
@@ -166,6 +178,11 @@ static int fq_codel_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt
                target = rta_getattr_u32(tb[TCA_FQ_CODEL_TARGET]);
                fprintf(f, "target %s ", sprint_time(target, b1));
        }
+       if (tb[TCA_FQ_CODEL_CE_THRESHOLD] &&
+           RTA_PAYLOAD(tb[TCA_FQ_CODEL_CE_THRESHOLD]) >= sizeof(__u32)) {
+               ce_threshold = rta_getattr_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]);
+               fprintf(f, "ce_threshold %s ", sprint_time(ce_threshold, b1));
+       }
        if (tb[TCA_FQ_CODEL_INTERVAL] &&
            RTA_PAYLOAD(tb[TCA_FQ_CODEL_INTERVAL]) >= sizeof(__u32)) {
                interval = rta_getattr_u32(tb[TCA_FQ_CODEL_INTERVAL]);
@@ -184,22 +201,26 @@ static int fq_codel_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt
 static int fq_codel_print_xstats(struct qdisc_util *qu, FILE *f,
                                 struct rtattr *xstats)
 {
-       struct tc_fq_codel_xstats *st;
+       struct tc_fq_codel_xstats _st, *st;
        SPRINT_BUF(b1);
 
        if (xstats == NULL)
                return 0;
 
-       if (RTA_PAYLOAD(xstats) < sizeof(*st))
-               return -1;
-
        st = RTA_DATA(xstats);
+       if (RTA_PAYLOAD(xstats) < sizeof(*st)) {
+               memset(&_st, 0, sizeof(_st));
+               memcpy(&_st, st, RTA_PAYLOAD(xstats));
+               st = &_st;
+       }
        if (st->type == TCA_FQ_CODEL_XSTATS_QDISC) {
                fprintf(f, "  maxpacket %u drop_overlimit %u new_flow_count %u ecn_mark %u",
                        st->qdisc_stats.maxpacket,
                        st->qdisc_stats.drop_overlimit,
                        st->qdisc_stats.new_flow_count,
                        st->qdisc_stats.ecn_mark);
+               if (st->qdisc_stats.ce_mark)
+                       fprintf(f, " ce_mark %u", st->qdisc_stats.ce_mark);
                fprintf(f, "\n  new_flows_len %u old_flows_len %u",
                        st->qdisc_stats.new_flows_len,
                        st->qdisc_stats.old_flows_len);