Subject: [PATCH] Add selective delay to sch_dealy (aka sch_ooo)

Hello!

David, please apply.
I tested it and works as expected.
Seems Stephen doesn't have time to look over.
Thank you very much.

Signed-off-by: Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>

--- linux-2.6.7-bk5.orig/net/sched/sch_delay.c 2004-06-23 12:18:00.000000000
+0300
+++ linux-2.6.7-bk5/net/sched/sch_delay.c 2004-06-24 10:41:02.000000000
+0300
@@ -7,6 +7,7 @@
* 2 of the License, or (at your option) any later version.
*
* Authors: Stephen Hemminger <[email protected]>
+ Catalin(ux aka Dino) BOIE <catab at umbrella dot ro>
*/

#include <linux/config.h>
@@ -33,7 +34,7 @@
#include <net/pkt_sched.h>

/* Network delay simulator
- This scheduler adds a fixed delay to all packets.
+ This scheduler adds a fixed delay to all/some packets.
Similar to NISTnet and BSD Dummynet.

It uses byte fifo underneath similar to TBF */
@@ -41,8 +42,12 @@ struct dly_sched_data {
u32 latency;
u32 limit;
u32 loss;
+ u32 gap; /* gap between packets: 0=all pkts are processed */
struct timer_list timer;
struct Qdisc *qdisc;
+ struct sk_buff_head qooo;
+ u32 send_from_qooo;
+ u32 counter;
};

/* Time stamp put into socket buffer control block */
@@ -59,6 +64,8 @@ static int dly_enqueue(struct sk_buff *s
struct dly_skb_cb *cb = (struct dly_skb_cb *)skb->cb;
int ret;

+ pr_debug("enqueue:\n");
+
/* Random packet drop 0 => none, ~0 => all */
if (q->loss >= net_random()) {
sch->stats.drops++;
@@ -104,6 +111,26 @@ static unsigned int dly_drop(struct Qdis
return len;
}

+static void dly_mod_timer(struct dly_sched_data *q, struct sk_buff *skb)
+{
+ struct dly_skb_cb *cb;
+ psched_time_t now;
+ long diff, delay;
+
+ if (timer_pending(&q->timer))
+ return;
+
+ cb = (struct dly_skb_cb *)skb->cb;
+ PSCHED_GET_TIME(now);
+ diff = q->latency - PSCHED_TDIFF(now, cb->queuetime);
+ delay = PSCHED_US2JIFFIE(diff);
+ if (delay <= 0)
+ delay = 1;
+ mod_timer(&q->timer, jiffies + delay);
+
+ pr_debug("mod_timer: Set new timer to %ld\n", jiffies + delay);
+}
+
/* Dequeue packet.
* If packet needs to be held up, then stop the
* queue and set timer to wakeup later.
@@ -111,37 +138,54 @@ static unsigned int dly_drop(struct Qdis
static struct sk_buff *dly_dequeue(struct Qdisc *sch)
{
struct dly_sched_data *q = (struct dly_sched_data *)sch->data;
- struct sk_buff *skb;
+ struct sk_buff *skb, *skb2;

- retry:
- skb = q->qdisc->dequeue(q->qdisc);
- if (skb) {
- struct dly_skb_cb *cb = (struct dly_skb_cb *)skb->cb;
- psched_time_t now;
- long diff, delay;
-
- PSCHED_GET_TIME(now);
- diff = q->latency - PSCHED_TDIFF(now, cb->queuetime);
-
- if (diff <= 0) {
- sch->q.qlen--;
- sch->flags &= ~TCQ_F_THROTTLED;
- return skb;
+ /* test if we must dequeue from qooo */
+ if (q->send_from_qooo == 1) {
+ q->send_from_qooo = 0;
+
+ skb = __skb_dequeue(&q->qooo);
+ if (skb == NULL) {
+ pr_debug("dequeue: BUG! send_from_qooo == 1 and queue
empty!\n");
+ return NULL;
}

- if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS)
{
- sch->q.qlen--;
- sch->stats.drops++;
- goto retry;
+ pr_debug("dequeue: from qooo queue [%p]\n", skb);
+ sch->q.qlen--;
+
+ /* set timer to next event */
+ skb2 = __skb_dequeue(&q->qooo);
+ if (skb2) {
+ dly_mod_timer(q, skb2);
+ __skb_queue_head(&q->qooo, skb2);
}

- delay = PSCHED_US2JIFFIE(diff);
- if (delay <= 0)
- delay = 1;
- mod_timer(&q->timer, jiffies+delay);
+ return skb;
+ }
+
+ skb = q->qdisc->dequeue(q->qdisc);
+ if (skb == NULL)
+ return NULL;
+
+ if (q->counter < q->gap) {
+ pr_debug("dequeue: don't touch this packet\n");
+ q->counter++;

- sch->flags |= TCQ_F_THROTTLED;
+ sch->q.qlen--;
+ sch->flags &= ~TCQ_F_THROTTLED;
+ return skb;
}
+
+ /* we must delay this packet */
+ pr_debug("dequeue: mv head pkt from main to qooo and mod timer\n");
+ q->send_from_qooo = 0;
+ dly_mod_timer(q, skb);
+ __skb_queue_tail(&q->qooo, skb);
+ sch->flags |= TCQ_F_THROTTLED;
+
+ /* reset counter */
+ q->counter = 0;
+
return NULL;
}

@@ -153,11 +197,16 @@ static void dly_reset(struct Qdisc *sch)
sch->q.qlen = 0;
sch->flags &= ~TCQ_F_THROTTLED;
del_timer(&q->timer);
+ skb_queue_purge(&q->qooo);
}

static void dly_timer(unsigned long arg)
{
struct Qdisc *sch = (struct Qdisc *)arg;
+ struct dly_sched_data *q = (struct dly_sched_data *)sch->data;
+
+ pr_debug("timer: Permit sending from qooo\n");
+ q->send_from_qooo = 1;

sch->flags &= ~TCQ_F_THROTTLED;
netif_schedule(sch->dev);
@@ -205,6 +254,10 @@ static int dly_change(struct Qdisc *sch,
q->latency = qopt->latency;
q->limit = qopt->limit;
q->loss = qopt->loss;
+ q->gap = qopt->gap;
+
+ q->counter = 0;
+ q->send_from_qooo = 0;
}
return err;
}
@@ -221,6 +274,8 @@ static int dly_init(struct Qdisc *sch, s
q->timer.data = (unsigned long) sch;
q->qdisc = &noop_qdisc;

+ skb_queue_head_init(&q->qooo);
+
return dly_change(sch, opt);
}

@@ -231,6 +286,7 @@ static void dly_destroy(struct Qdisc *sc
del_timer(&q->timer);
qdisc_destroy(q->qdisc);
q->qdisc = &noop_qdisc;
+ skb_queue_purge(&q->qooo);
}

static int dly_dump(struct Qdisc *sch, struct sk_buff *skb)
@@ -242,6 +298,7 @@ static int dly_dump(struct Qdisc *sch, s
qopt.latency = q->latency;
qopt.limit = q->limit;
qopt.loss = q->loss;
+ qopt.gap = q->gap;

RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt);

--- linux-2.6.7-bk5.orig/include/linux/pkt_sched.h 2004-06-23
12:17:59.000000000 +0300
+++ linux-2.6.7-bk5/include/linux/pkt_sched.h 2004-06-23 14:40:16.000000000
+0300
@@ -438,5 +438,6 @@ struct tc_dly_qopt
__u32 latency;
__u32 limit;
__u32 loss;
+ __u32 gap;
};
#endif

---
Catalin(ux aka Dino) BOIE
catab at deuroconsult.ro
http://kernel.umbrella.ro/


2004-06-28 16:45:45

by Stephen Hemminger

[permalink] [raw]
Subject: Re: [PATCH] Add selective delay to sch_dealy (aka sch_ooo)

I am working on an expanded version of the combined scheduler.
So if you wait a couple days, it should be ready.