From: Stephen Hemminger <shemminger@vyatta.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
Patrick McHardy <kaber@trash.net>, jamal <hadi@cyberus.ca>,
Jarek Poplawski <jarkao2@gmail.com>
Subject: Re: [PATCH] net_sched: accurate bytes/packets stats/rates
Date: Fri, 14 Jan 2011 11:03:42 -0800 [thread overview]
Message-ID: <20110114110342.4d95ad5b@nehalam> (raw)
In-Reply-To: <1295028502.3937.116.camel@edumazet-laptop>
>From Eric Dumazet <eric.dumazet@gmail.com>
In commit 44b8288308ac9d (net_sched: pfifo_head_drop problem), we fixed
a problem with pfifo_head drops that incorrectly decreased
sch->bstats.bytes and sch->bstats.packets
Several qdiscs (CHOKe, SFQ, pfifo_head, ...) are able to drop a
previously enqueued packet, and bstats cannot be changed, so
bstats/rates are not accurate (over estimated)
This patch changes the qdisc_bstats updates to be done at dequeue() time
instead of enqueue() time. bstats counters no longer account for dropped
frames, and rates are more correct, since enqueue() bursts dont have
effect on dequeue() rate.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Jarek Poplawski <jarkao2@gmail.com>
CC: jamal <hadi@cyberus.ca>
---
sch_fifo now changed to use __qdisc_queue_drop_head which
keeps correct statistics and is actually clearer.
include/net/sch_generic.h | 8 +++++---
net/sched/sch_cbq.c | 3 +--
net/sched/sch_drr.c | 2 +-
net/sched/sch_dsmark.c | 2 +-
net/sched/sch_fifo.c | 6 +-----
net/sched/sch_hfsc.c | 2 +-
net/sched/sch_htb.c | 12 +++++-------
net/sched/sch_multiq.c | 2 +-
net/sched/sch_netem.c | 3 +--
net/sched/sch_prio.c | 2 +-
net/sched/sch_red.c | 11 ++++++-----
net/sched/sch_sfq.c | 5 ++---
net/sched/sch_tbf.c | 2 +-
net/sched/sch_teql.c | 3 ++-
14 files changed, 29 insertions(+), 34 deletions(-)
--- a/include/net/sch_generic.h 2011-01-14 09:19:00.730849868 -0800
+++ b/include/net/sch_generic.h 2011-01-14 09:47:59.058551676 -0800
@@ -445,7 +445,6 @@ static inline int __qdisc_enqueue_tail(s
{
__skb_queue_tail(list, skb);
sch->qstats.backlog += qdisc_pkt_len(skb);
- qdisc_bstats_update(sch, skb);
return NET_XMIT_SUCCESS;
}
@@ -460,8 +459,10 @@ static inline struct sk_buff *__qdisc_de
{
struct sk_buff *skb = __skb_dequeue(list);
- if (likely(skb != NULL))
+ if (likely(skb != NULL)) {
sch->qstats.backlog -= qdisc_pkt_len(skb);
+ qdisc_bstats_update(sch, skb);
+ }
return skb;
}
@@ -474,10 +475,11 @@ static inline struct sk_buff *qdisc_dequ
static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
struct sk_buff_head *list)
{
- struct sk_buff *skb = __qdisc_dequeue_head(sch, list);
+ struct sk_buff *skb = __skb_dequeue(list);
if (likely(skb != NULL)) {
unsigned int len = qdisc_pkt_len(skb);
+ sch->qstats.backlog -= len;
kfree_skb(skb);
return len;
}
--- a/net/sched/sch_cbq.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_cbq.c 2011-01-14 09:28:20.398631228 -0800
@@ -390,7 +390,6 @@ cbq_enqueue(struct sk_buff *skb, struct
ret = qdisc_enqueue(skb, cl->q);
if (ret == NET_XMIT_SUCCESS) {
sch->q.qlen++;
- qdisc_bstats_update(sch, skb);
cbq_mark_toplevel(q, cl);
if (!cl->next_alive)
cbq_activate_class(cl);
@@ -649,7 +648,6 @@ static int cbq_reshape_fail(struct sk_bu
ret = qdisc_enqueue(skb, cl->q);
if (ret == NET_XMIT_SUCCESS) {
sch->q.qlen++;
- qdisc_bstats_update(sch, skb);
if (!cl->next_alive)
cbq_activate_class(cl);
return 0;
@@ -971,6 +969,7 @@ cbq_dequeue(struct Qdisc *sch)
skb = cbq_dequeue_1(sch);
if (skb) {
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
sch->flags &= ~TCQ_F_THROTTLED;
return skb;
--- a/net/sched/sch_drr.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_drr.c 2011-01-14 09:28:20.398631228 -0800
@@ -376,7 +376,6 @@ static int drr_enqueue(struct sk_buff *s
}
bstats_update(&cl->bstats, skb);
- qdisc_bstats_update(sch, skb);
sch->q.qlen++;
return err;
@@ -403,6 +402,7 @@ static struct sk_buff *drr_dequeue(struc
skb = qdisc_dequeue_peeked(cl->qdisc);
if (cl->qdisc->q.qlen == 0)
list_del(&cl->alist);
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
return skb;
}
--- a/net/sched/sch_dsmark.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_dsmark.c 2011-01-14 09:28:20.398631228 -0800
@@ -260,7 +260,6 @@ static int dsmark_enqueue(struct sk_buff
return err;
}
- qdisc_bstats_update(sch, skb);
sch->q.qlen++;
return NET_XMIT_SUCCESS;
@@ -283,6 +282,7 @@ static struct sk_buff *dsmark_dequeue(st
if (skb == NULL)
return NULL;
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
index = skb->tc_index & (p->indices - 1);
--- a/net/sched/sch_fifo.c 2011-01-09 09:34:32.690685246 -0800
+++ b/net/sched/sch_fifo.c 2011-01-14 10:43:39.534246186 -0800
@@ -46,17 +46,14 @@ static int pfifo_enqueue(struct sk_buff
static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
- struct sk_buff *skb_head;
struct fifo_sched_data *q = qdisc_priv(sch);
if (likely(skb_queue_len(&sch->q) < q->limit))
return qdisc_enqueue_tail(skb, sch);
/* queue full, remove one skb to fulfill the limit */
- skb_head = qdisc_dequeue_head(sch);
+ __qdisc_queue_drop_head(sch, &sch->q);
sch->qstats.drops++;
- kfree_skb(skb_head);
-
qdisc_enqueue_tail(skb, sch);
return NET_XMIT_CN;
--- a/net/sched/sch_hfsc.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_hfsc.c 2011-01-14 09:28:20.428633918 -0800
@@ -1600,7 +1600,6 @@ hfsc_enqueue(struct sk_buff *skb, struct
set_active(cl, qdisc_pkt_len(skb));
bstats_update(&cl->bstats, skb);
- qdisc_bstats_update(sch, skb);
sch->q.qlen++;
return NET_XMIT_SUCCESS;
@@ -1666,6 +1665,7 @@ hfsc_dequeue(struct Qdisc *sch)
}
sch->flags &= ~TCQ_F_THROTTLED;
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
return skb;
--- a/net/sched/sch_htb.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_htb.c 2011-01-14 09:28:20.438634799 -0800
@@ -574,7 +574,6 @@ static int htb_enqueue(struct sk_buff *s
}
sch->q.qlen++;
- qdisc_bstats_update(sch, skb);
return NET_XMIT_SUCCESS;
}
@@ -842,7 +841,7 @@ next:
static struct sk_buff *htb_dequeue(struct Qdisc *sch)
{
- struct sk_buff *skb = NULL;
+ struct sk_buff *skb;
struct htb_sched *q = qdisc_priv(sch);
int level;
psched_time_t next_event;
@@ -851,6 +850,8 @@ static struct sk_buff *htb_dequeue(struc
/* try to dequeue direct packets as high prio (!) to minimize cpu work */
skb = __skb_dequeue(&q->direct_queue);
if (skb != NULL) {
+ok:
+ qdisc_bstats_update(sch, skb);
sch->flags &= ~TCQ_F_THROTTLED;
sch->q.qlen--;
return skb;
@@ -884,11 +885,8 @@ static struct sk_buff *htb_dequeue(struc
int prio = ffz(m);
m |= 1 << prio;
skb = htb_dequeue_tree(q, prio, level);
- if (likely(skb != NULL)) {
- sch->q.qlen--;
- sch->flags &= ~TCQ_F_THROTTLED;
- goto fin;
- }
+ if (likely(skb != NULL))
+ goto ok;
}
}
sch->qstats.overlimits++;
--- a/net/sched/sch_multiq.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_multiq.c 2011-01-14 09:28:20.438634799 -0800
@@ -83,7 +83,6 @@ multiq_enqueue(struct sk_buff *skb, stru
ret = qdisc_enqueue(skb, qdisc);
if (ret == NET_XMIT_SUCCESS) {
- qdisc_bstats_update(sch, skb);
sch->q.qlen++;
return NET_XMIT_SUCCESS;
}
@@ -112,6 +111,7 @@ static struct sk_buff *multiq_dequeue(st
qdisc = q->queues[q->curband];
skb = qdisc->dequeue(qdisc);
if (skb) {
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
return skb;
}
--- a/net/sched/sch_netem.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_netem.c 2011-01-14 09:28:20.438634799 -0800
@@ -240,7 +240,6 @@ static int netem_enqueue(struct sk_buff
if (likely(ret == NET_XMIT_SUCCESS)) {
sch->q.qlen++;
- qdisc_bstats_update(sch, skb);
} else if (net_xmit_drop_count(ret)) {
sch->qstats.drops++;
}
@@ -289,6 +288,7 @@ static struct sk_buff *netem_dequeue(str
skb->tstamp.tv64 = 0;
#endif
pr_debug("netem_dequeue: return skb=%p\n", skb);
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
return skb;
}
@@ -476,7 +476,6 @@ static int tfifo_enqueue(struct sk_buff
__skb_queue_after(list, skb, nskb);
sch->qstats.backlog += qdisc_pkt_len(nskb);
- qdisc_bstats_update(sch, nskb);
return NET_XMIT_SUCCESS;
}
--- a/net/sched/sch_prio.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_prio.c 2011-01-14 09:28:20.438634799 -0800
@@ -84,7 +84,6 @@ prio_enqueue(struct sk_buff *skb, struct
ret = qdisc_enqueue(skb, qdisc);
if (ret == NET_XMIT_SUCCESS) {
- qdisc_bstats_update(sch, skb);
sch->q.qlen++;
return NET_XMIT_SUCCESS;
}
@@ -116,6 +115,7 @@ static struct sk_buff *prio_dequeue(stru
struct Qdisc *qdisc = q->queues[prio];
struct sk_buff *skb = qdisc->dequeue(qdisc);
if (skb) {
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
return skb;
}
--- a/net/sched/sch_red.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_red.c 2011-01-14 09:28:20.438634799 -0800
@@ -94,7 +94,6 @@ static int red_enqueue(struct sk_buff *s
ret = qdisc_enqueue(skb, child);
if (likely(ret == NET_XMIT_SUCCESS)) {
- qdisc_bstats_update(sch, skb);
sch->q.qlen++;
} else if (net_xmit_drop_count(ret)) {
q->stats.pdrop++;
@@ -114,11 +113,13 @@ static struct sk_buff * red_dequeue(stru
struct Qdisc *child = q->qdisc;
skb = child->dequeue(child);
- if (skb)
+ if (skb) {
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
- else if (!red_is_idling(&q->parms))
- red_start_of_idle_period(&q->parms);
-
+ } else {
+ if (!red_is_idling(&q->parms))
+ red_start_of_idle_period(&q->parms);
+ }
return skb;
}
--- a/net/sched/sch_sfq.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_sfq.c 2011-01-14 09:28:20.438634799 -0800
@@ -402,10 +402,8 @@ sfq_enqueue(struct sk_buff *skb, struct
q->tail = slot;
slot->allot = q->scaled_quantum;
}
- if (++sch->q.qlen <= q->limit) {
- qdisc_bstats_update(sch, skb);
+ if (++sch->q.qlen <= q->limit)
return NET_XMIT_SUCCESS;
- }
sfq_drop(sch);
return NET_XMIT_CN;
@@ -445,6 +443,7 @@ next_slot:
}
skb = slot_dequeue_head(slot);
sfq_dec(q, a);
+ qdisc_bstats_update(sch, skb);
sch->q.qlen--;
sch->qstats.backlog -= qdisc_pkt_len(skb);
--- a/net/sched/sch_tbf.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_tbf.c 2011-01-14 09:28:20.438634799 -0800
@@ -134,7 +134,6 @@ static int tbf_enqueue(struct sk_buff *s
}
sch->q.qlen++;
- qdisc_bstats_update(sch, skb);
return NET_XMIT_SUCCESS;
}
@@ -187,6 +186,7 @@ static struct sk_buff *tbf_dequeue(struc
q->ptokens = ptoks;
sch->q.qlen--;
sch->flags &= ~TCQ_F_THROTTLED;
+ qdisc_bstats_update(sch, skb);
return skb;
}
--- a/net/sched/sch_teql.c 2011-01-14 09:19:00.830857886 -0800
+++ b/net/sched/sch_teql.c 2011-01-14 09:28:20.438634799 -0800
@@ -83,7 +83,6 @@ teql_enqueue(struct sk_buff *skb, struct
if (q->q.qlen < dev->tx_queue_len) {
__skb_queue_tail(&q->q, skb);
- qdisc_bstats_update(sch, skb);
return NET_XMIT_SUCCESS;
}
@@ -107,6 +106,8 @@ teql_dequeue(struct Qdisc* sch)
dat->m->slaves = sch;
netif_wake_queue(m);
}
+ } else {
+ qdisc_bstats_update(sch, skb);
}
sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
return skb;
next prev parent reply other threads:[~2011-01-14 19:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-14 16:16 [PATCH] net_sched: accurate bytes/packets stats/rates Eric Dumazet
2011-01-14 17:52 ` Stephen Hemminger
2011-01-14 18:08 ` Eric Dumazet
2011-01-14 19:03 ` Stephen Hemminger [this message]
2011-01-14 19:21 ` Eric Dumazet
2011-01-16 22:35 ` Jarek Poplawski
2011-01-17 0:09 ` Changli Gao
2011-01-17 7:17 ` Eric Dumazet
2011-01-17 9:16 ` Hagen Paul Pfeifer
2011-01-17 6:54 ` Eric Dumazet
2011-01-21 7:31 ` David Miller
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