Subject: Re: [BUG #12364] Re: HTB - very bad precision? HFSC works fine! 2.6.28

From: Jarek Poplawski <[email-masked]>
Date: Fri, 9 Jan 2009 07:24:52 +0000

On Thu, Jan 08, 2009 at 05:27:31PM -0000, [email-masked] wrote:
> I asume there's some issue with the NIC Driver os the kernel modules with
> the 1000Mbit NIC's? am i correct?

In this case the issue is packet schedulers usually don't work with
gso/tso enabled, at least without some tweaking with mtu. Some qdisc
get inacurrate, others (like tbf) can drop too big packets (have a
look at "dropped" stats).

BTW, Jorge, since my tries to Cc bugzilla failed, please add some
comment to your bug report (I guess it could be closed too).

Thanks
Jarek P.

> 
> 
> > An active connection when running this commands:
> > (now it seams to work, the 200Kbit i defined, are gaving me 22.5/23Kbyte
> > /sec)
> >
> > Did you catch it?
> >
> >
> > lira:~# ethtool -k eth0
> > Offload parameters for eth0:
> > Cannot get device flags: Operation not supported
> > rx-checksumming: on
> > tx-checksumming: on
> > scatter-gather: off
> > tcp segmentation offload: off
> > udp fragmentation offload: off
> > generic segmentation offload: off
> > large receive offload: off
> > lira:~# tc -s qdisc show dev eth0
> > qdisc cbq 1: root rate 12500000bps (bounded,isolated) prio no-transmit
> >  Sent 5336353 bytes 5737 pkts (dropped 16, overlimits 1382)
> >  backlog 8p
> >   borrowed 0 overactions 0 avgidle 78 undertime 0
> >
> >  qdisc tbf 1280: parent 1:1280 rate 25000bps burst 10Kb lat 209.7ms
> >  Sent 441812 bytes 310 pkts (dropped 16, overlimits 2215)
> >  backlog 8p
> >
> > lira:~# tc -s class show dev eth0
> > class cbq 1: root rate 12500000bps (bounded,isolated) prio no-transmit
> >  Sent 5128779 bytes 5827 pkts (dropped 0, overlimits 0)
> >   borrowed 0 overactions 0 avgidle 78 undertime 0
> > class cbq 1:1280 parent 1: leaf 1280: rate 25000bps (bounded,isolated)
> > prio 5
> >  Sent 811784 bytes 568 pkts (dropped 22, overlimits 0)
> >  backlog 9p
> >   borrowed 0 overactions 0 avgidle 4507 undertime 0
> > class tbf 1280:1 parent 1280: [UNKNOWN]
> >  Sent 0 bytes 0 pkts (dropped 0, overlimits 0)
> >
> >
> >
> >
> >
> >> Could you try to check this with scatter-gather and tcp segmentation
> >> offload off too? If there is no difference please send the stats
> >> again both for working and non-working case.
> >>
> >> Thanks,
> >> Jarek P.
> >>
> >
> >
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> 
>