Date: Wed, 21 Nov 2001 15:02:49 -0800 From: rick norman <rnorman@ikaika.com> To: Luigi Rizzo <rizzo@aciri.org> Cc: freebsd-hackers@freebsd.org Subject: Re: dummynet "pipe show" problem Message-ID: <3BFC3299.E7DBA702@ikaika.com> References: <3BDEF5C5.F5D604C2@lmco.com> <20011030113914.H9665@iguana.aciri.org>
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Hi,
I'm still running into lots of problems with this on 4.3. Is it neccessary
to introduce a delay in the pipe ? Would a delay of zero work ?
Has this been fixed in 4.4 ?
Rick
Luigi Rizzo wrote:
> On Tue, Oct 30, 2001 at 10:47:33AM -0800, rick norman wrote:
> > Hi,
> > I have enclosed a short piece of code that seems to
> > reproduce the problem after 5 to 10 minutes.
> > I am running 4.3 freebsd off the release cd's.
> > Pretty much the generic kernel except for the
> > addition of dummynet and ipfw. My platform
> > is a dell dimension 4100 with 1ghz p3, though
> > I doubt that is relevant. To reproduce the problem,
> > compile and run the enclosed code in one window.
> > In another window su to root and run "ping -s 1024 -f 127.0.42.1".
> > As you will see, the code reports the gowing byte count as one
> > would expect. Walk away for 5 to 10 minutes and when you come
> > back you should see the state I'm talking about. The flood ping stream
>
> It _might_ be a locking problem due to the frequent
> reconfigurations of the pipe -- i think there was some
> fix of this kind related to ipfw commands between 4.3 and 4.4.
> I will see if i can reproduce the problem locally (but i have
> 4.4).
>
> You are using dummynet in a very peculiar way:
> more precisely, your pipe does not introduce any delay,
> and this excludes the scheduler which is part of dummynet.
> Also you are using the same pipe for icmp requests
> and replies, which are generated within the kernel, so
> the behaviour should be quite deterministic in this
> respect.
>
> thanks for the report
>
> luigi
>
> > Thanks,
> > Rick
> >
> > ----------------------cut--------------------------------------------
> >
> > main() {
> > int i;
> >
> > restart:
> > system("ifconfig lo0 -alias 127.0.42.1");
> > system("ifconfig lo0 alias 127.0.42.1 netmask 255.255.255.0");
> > system("ipfw -f flush");
> > system("ipfw pipe 1 delete");
> > system("ipfw add pipe 1 ip from 127.0.42.0/24 to any in");
> >
> > for(i=0;i<5;i++) {
> > system("ipfw pipe 1 config queue 2048Bytes");
> > sleep(1);
> > system("ipfw pipe 1 show");
> > }
> >
> > goto restart;
> > }
> >
> > --------------------cut--------------------------------------
> >
> >
> >
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