Waskiewicz Jr, Peter P wrote:
>>[...]
>>The only reasonable thing it can do is not care about
>>multiqueue and just dequeue as usual. In fact I think it
>>should be an error to configure multiqueue on a non-root qdisc.
>
>
> Ack. This is a thought process that trips me up from time to time...I
> see child qdisc, and think that's the last qdisc to dequeue and send to
> the device, not the first one to dequeue. So please disregard my
> comments before; I totally agree with you. Great catch here; I really
> like the prio_classify() cleanup.
Thanks. This updated patch makes configuring a non-root qdisc for
multiqueue an error.
[SCHED] Qdisc changes and sch_rr added for multiqueue
Add the new sch_rr qdisc for multiqueue network device support.
Allow sch_prio and sch_rr to be compiled with or without multiqueue
hardware support.
sch_rr is part of sch_prio, and is referenced from MODULE_ALIAS. This
was done since sch_prio and sch_rr only differ in their dequeue routine.
Signed-off-by: Peter P Waskiewicz Jr <[EMAIL PROTECTED]>
Signed-off-by: Patrick McHardy <[EMAIL PROTECTED]>
---
commit 8798d6bf4f3ed4f5b162184282adc714ef5b69b1
tree b3ba373a0534b905b34abc520eba6adecdcc3ca5
parent 48e334930c5fbb64a821733a7056e2800057c128
author Peter P Waskiewicz Jr <[EMAIL PROTECTED]> Thu, 28 Jun 2007 18:47:49 +0200
committer Patrick McHardy <[EMAIL PROTECTED]> Thu, 28 Jun 2007 21:23:44 +0200
include/linux/pkt_sched.h | 9 +++
net/sched/Kconfig | 11 ++++
net/sched/sch_prio.c | 129 ++++++++++++++++++++++++++++++++++++++++-----
3 files changed, 134 insertions(+), 15 deletions(-)
diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index d10f353..268c515 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -101,6 +101,15 @@ struct tc_prio_qopt
__u8 priomap[TC_PRIO_MAX+1]; /* Map: logical priority -> PRIO band */
};
+enum
+{
+ TCA_PRIO_UNSPEC,
+ TCA_PRIO_MQ,
+ __TCA_PRIO_MAX
+};
+
+#define TCA_PRIO_MAX (__TCA_PRIO_MAX - 1)
+
/* TBF section */
struct tc_tbf_qopt
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 475df84..f321794 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -111,6 +111,17 @@ config NET_SCH_PRIO
To compile this code as a module, choose M here: the
module will be called sch_prio.
+config NET_SCH_RR
+ tristate "Multi Band Round Robin Queuing (RR)"
+ select NET_SCH_PRIO
+ ---help---
+ Say Y here if you want to use an n-band round robin packet
+ scheduler.
+
+ The module uses sch_prio for its framework and is aliased as
+ sch_rr, so it will load sch_prio, although it is referred
+ to using sch_rr.
+
config NET_SCH_RED
tristate "Random Early Detection (RED)"
---help---
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 6d7542c..4045220 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -40,9 +40,11 @@
struct prio_sched_data
{
int bands;
+ int curband; /* for round-robin */
struct tcf_proto *filter_list;
u8 prio2band[TC_PRIO_MAX+1];
struct Qdisc *queues[TCQ_PRIO_BANDS];
+ int mq;
};
@@ -70,14 +72,17 @@ prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
#endif
if (TC_H_MAJ(band))
band = 0;
- return q->queues[q->prio2band[band&TC_PRIO_MAX]];
+ band = q->prio2band[band&TC_PRIO_MAX];
+ goto out;
}
band = res.classid;
}
band = TC_H_MIN(band) - 1;
if (band >= q->bands)
- return q->queues[q->prio2band[0]];
-
+ band = q->prio2band[0];
+out:
+ if (q->mq)
+ skb_set_queue_mapping(skb, band);
return q->queues[band];
}
@@ -144,17 +149,58 @@ prio_dequeue(struct Qdisc* sch)
struct Qdisc *qdisc;
for (prio = 0; prio < q->bands; prio++) {
- qdisc = q->queues[prio];
- skb = qdisc->dequeue(qdisc);
- if (skb) {
- sch->q.qlen--;
- return skb;
+ /* Check if the target subqueue is available before
+ * pulling an skb. This way we avoid excessive requeues
+ * for slower queues.
+ */
+ if (!netif_subqueue_stopped(sch->dev, (q->mq ? prio : 0))) {
+ qdisc = q->queues[prio];
+ skb = qdisc->dequeue(qdisc);
+ if (skb) {
+ sch->q.qlen--;
+ return skb;
+ }
}
}
return NULL;
}
+static struct sk_buff *rr_dequeue(struct Qdisc* sch)
+{
+ struct sk_buff *skb;
+ struct prio_sched_data *q = qdisc_priv(sch);
+ struct Qdisc *qdisc;
+ int bandcount;
+
+ /* Only take one pass through the queues. If nothing is available,
+ * return nothing.
+ */
+ for (bandcount = 0; bandcount < q->bands; bandcount++) {
+ /* Check if the target subqueue is available before
+ * pulling an skb. This way we avoid excessive requeues
+ * for slower queues. If the queue is stopped, try the
+ * next queue.
+ */
+ if (!netif_subqueue_stopped(sch->dev,
+ (q->mq ? q->curband : 0))) {
+ qdisc = q->queues[q->curband];
+ skb = qdisc->dequeue(qdisc);
+ if (skb) {
+ sch->q.qlen--;
+ q->curband++;
+ if (q->curband >= q->bands)
+ q->curband = 0;
+ return skb;
+ }
+ }
+ q->curband++;
+ if (q->curband >= q->bands)
+ q->curband = 0;
+ }
+ return NULL;
+}
+
static unsigned int prio_drop(struct Qdisc* sch)
{
struct prio_sched_data *q = qdisc_priv(sch);
@@ -198,21 +244,41 @@ prio_destroy(struct Qdisc* sch)
static int prio_tune(struct Qdisc *sch, struct rtattr *opt)
{
struct prio_sched_data *q = qdisc_priv(sch);
- struct tc_prio_qopt *qopt = RTA_DATA(opt);
+ struct tc_prio_qopt *qopt;
+ struct rtattr *tb[TCA_PRIO_MAX];
int i;
- if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
+ if (rtattr_parse_nested_compat(tb, TCA_PRIO_MAX, opt, qopt,
+ sizeof(*qopt)))
return -EINVAL;
- if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
+ q->bands = qopt->bands;
+ /* If we're multiqueue, make sure the number of incoming bands
+ * matches the number of queues on the device we're associating with.
+ * If the number of bands requested is zero, then set q->bands to
+ * dev->egress_subqueue_count.
+ */
+ q->mq = RTA_GET_FLAG(tb[TCA_PRIO_MQ - 1]);
+ if (q->mq) {
+ if (sch->handle != TC_H_ROOT)
+ return -EINVAL;
+ if (netif_is_multiqueue(sch->dev)) {
+ if (q->bands == 0)
+ q->bands = sch->dev->egress_subqueue_count;
+ else if (q->bands != sch->dev->egress_subqueue_count)
+ return -EINVAL;
+ } else
+ return -EOPNOTSUPP;
+ }
+
+ if (q->bands > TCQ_PRIO_BANDS || q->bands < 2)
return -EINVAL;
for (i=0; i<=TC_PRIO_MAX; i++) {
- if (qopt->priomap[i] >= qopt->bands)
+ if (qopt->priomap[i] >= q->bands)
return -EINVAL;
}
sch_tree_lock(sch);
- q->bands = qopt->bands;
memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
for (i=q->bands; i<TCQ_PRIO_BANDS; i++) {
@@ -268,11 +334,17 @@ static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct prio_sched_data *q = qdisc_priv(sch);
unsigned char *b = skb_tail_pointer(skb);
+ struct rtattr *nest;
struct tc_prio_qopt opt;
opt.bands = q->bands;
memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1);
- RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+
+ nest = RTA_NEST_COMPAT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+ if (q->mq)
+ RTA_PUT_FLAG(skb, TCA_PRIO_MQ);
+ RTA_NEST_COMPAT_END(skb, nest);
+
return skb->len;
rtattr_failure:
@@ -443,17 +515,44 @@ static struct Qdisc_ops prio_qdisc_ops = {
.owner = THIS_MODULE,
};
+static struct Qdisc_ops rr_qdisc_ops = {
+ .next = NULL,
+ .cl_ops = &prio_class_ops,
+ .id = "rr",
+ .priv_size = sizeof(struct prio_sched_data),
+ .enqueue = prio_enqueue,
+ .dequeue = rr_dequeue,
+ .requeue = prio_requeue,
+ .drop = prio_drop,
+ .init = prio_init,
+ .reset = prio_reset,
+ .destroy = prio_destroy,
+ .change = prio_tune,
+ .dump = prio_dump,
+ .owner = THIS_MODULE,
+};
+
static int __init prio_module_init(void)
{
- return register_qdisc(&prio_qdisc_ops);
+ int err;
+
+ err = register_qdisc(&prio_qdisc_ops);
+ if (err < 0)
+ return err;
+ err = register_qdisc(&rr_qdisc_ops);
+ if (err < 0)
+ unregister_qdisc(&prio_qdisc_ops);
+ return err;
}
static void __exit prio_module_exit(void)
{
unregister_qdisc(&prio_qdisc_ops);
+ unregister_qdisc(&rr_qdisc_ops);
}
module_init(prio_module_init)
module_exit(prio_module_exit)
MODULE_LICENSE("GPL");
+MODULE_ALIAS("sch_rr");
