net_sched: sch_fq: add TCA_FQ_WEIGHTS attribute

This attribute can be used to tune the per band weight
and report them in "tc qdisc show" output:

qdisc fq 802f: parent 1:9 limit 100000p flow_limit 500p buckets 1024 orphan_mask 1023
 quantum 8364b initial_quantum 41820b low_rate_threshold 550Kbit
 refill_delay 40ms timer_slack 10us horizon 10s horizon_drop
 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 weights 589824 196608 65536
 Sent 236460814 bytes 792991 pkt (dropped 0, overlimits 0 requeues 0)
 rate 25816bit 10pps backlog 0b 0p requeues 0
  flows 4 (inactive 4 throttled 0)
  gc 0 throttled 19 latency 17.6us fastpath 773882

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index ec5ab44d41a2493130670870dc9e68c71187740f..f762a10bfb78ed896d8a5b936045a956d97b3831 100644 (file)
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -943,12 +943,15 @@ enum {
 
        TCA_FQ_PRIOMAP,         /* prio2band */
 
+       TCA_FQ_WEIGHTS,         /* Weights for each band */
+
        __TCA_FQ_MAX
 };
 
 #define TCA_FQ_MAX     (__TCA_FQ_MAX - 1)
 
 #define FQ_BANDS 3
+#define FQ_MIN_WEIGHT 16384
 
 struct tc_fq_qd_stats {
        __u64   gc_flows;

diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 081105801fa674a74a570027e4681873aed0430f..8eacdb54e72f4412af1834bfdb2c387d41516349 100644 (file)
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -919,6 +919,10 @@ static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = {
                        .type = NLA_BINARY,
                        .len = sizeof(struct tc_prio_qopt),
                },
+       [TCA_FQ_WEIGHTS]                = {
+                       .type = NLA_BINARY,
+                       .len = FQ_BANDS * sizeof(s32),
+               },
 };
 
 /* compress a u8 array with all elems <= 3 to an array of 2-bit fields */
@@ -941,6 +945,25 @@ static void fq_prio2band_decompress_crumb(const u8 *in, u8 *out)
                out[i] = fq_prio2band(in, i);
 }
 
+static int fq_load_weights(struct fq_sched_data *q,
+                          const struct nlattr *attr,
+                          struct netlink_ext_ack *extack)
+{
+       s32 *weights = nla_data(attr);
+       int i;
+
+       for (i = 0; i < FQ_BANDS; i++) {
+               if (weights[i] < FQ_MIN_WEIGHT) {
+                       NL_SET_ERR_MSG_FMT_MOD(extack, "Weight %d less that minimum allowed %d",
+                                              weights[i], FQ_MIN_WEIGHT);
+                       return -EINVAL;
+               }
+       }
+       for (i = 0; i < FQ_BANDS; i++)
+               q->band_flows[i].quantum = weights[i];
+       return 0;
+}
+
 static int fq_load_priomap(struct fq_sched_data *q,
                           const struct nlattr *attr,
                           struct netlink_ext_ack *extack)
@@ -1040,6 +1063,9 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt,
        if (!err && tb[TCA_FQ_PRIOMAP])
                err = fq_load_priomap(q, tb[TCA_FQ_PRIOMAP], extack);
 
+       if (!err && tb[TCA_FQ_WEIGHTS])
+               err = fq_load_weights(q, tb[TCA_FQ_WEIGHTS], extack);
+
        if (tb[TCA_FQ_ORPHAN_MASK])
                q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]);
 
@@ -1142,6 +1168,7 @@ static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
        };
        u64 horizon = q->horizon;
        struct nlattr *opts;
+       s32 weights[3];
 
        opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
        if (opts == NULL)
@@ -1175,6 +1202,12 @@ static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
        if (nla_put(skb, TCA_FQ_PRIOMAP, sizeof(prio), &prio))
                goto nla_put_failure;
 
+       weights[0] = q->band_flows[0].quantum;
+       weights[1] = q->band_flows[1].quantum;
+       weights[2] = q->band_flows[2].quantum;
+       if (nla_put(skb, TCA_FQ_WEIGHTS, sizeof(weights), &weights))
+               goto nla_put_failure;
+
        return nla_nest_end(skb, opts);
 
 nla_put_failure: