Re: Possible regression in HTB

Submitted by Jarek Poplawski on Oct. 8, 2008, 7:46 a.m.

Details

Message ID 20081008074604.GC4174@ff.dom.local
State Accepted
Delegated to: David Miller
Headers show

Commit Message

Jarek Poplawski Oct. 8, 2008, 7:46 a.m. 
On Wed, Oct 08, 2008 at 10:06:38AM +0300, Denys Fedoryshchenko wrote:
> On Wednesday 08 October 2008, Jarek Poplawski wrote:
> > On Wed, Oct 08, 2008 at 02:31:26AM +0200, Patrick McHardy wrote:
> > ...
> >
> > > I'm pretty sure that the differences are caused by HTB not being
> > > in control of the queue since the device is the real bottleneck
> > > in this configuration.
> >
> > Yes, otherwise there would be no requeuing. And, btw. the golden rule
> > of scheduling/shaping is limiting below "hardware" limits.
> By the way, HTB counting ethernet headers (e.g. if you send 1500 byte ping, it 
> will be 1514 in tc counters) . So possible ethernet overhead counted.
> 

Right, that's why stats from the other host could differ and these
tc stats mentioned by Patrick could be useful.

BTW, current requeuing isn't true requeuing, but we should have some
info about this, so something like this patch is needed.

Jarek P.

-------------->

pkt_sched: Update qdisc requeue stats in dev_requeue_skb()

After the last change of requeuing there is no info about such
incidents in tc stats. This patch updates the counter, but we should
consider this should differ from previous stats because of additional
checks preventing to repeat this. On the other hand, previous stats
didn't include requeuing of gso_segmented skbs.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>

---

 net/sched/sch_generic.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

David Miller Oct. 8, 2008, 6:36 p.m. 
From: Jarek Poplawski <jarkao2@gmail.com>
Date: Wed, 8 Oct 2008 07:46:04 +0000

> pkt_sched: Update qdisc requeue stats in dev_requeue_skb()
> 
> After the last change of requeuing there is no info about such
> incidents in tc stats. This patch updates the counter, but we should
> consider this should differ from previous stats because of additional
> checks preventing to repeat this. On the other hand, previous stats
> didn't include requeuing of gso_segmented skbs.
> 
> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>

Applied to net-next-2.6, thanks Jarek.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch hide | download patch | download mbox 

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 31f6b61..7b5572d 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -45,6 +45,7 @@  static inline int qdisc_qlen(struct Qdisc *q)
 static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
 {
 	q->gso_skb = skb;
+	q->qstats.requeues++;
 	__netif_schedule(q);
 
 	return 0;