[ixp1200] peth driver question, need help

[huangtao]

thanks for your help

but the packets rate is very slow, I start just two ping windows from windows 2000.
each windows ping the same ip address of the peth.   and the total descriptor is 1000, 
I think the descriptor would not usr off.

----- Original Message ----- 
From: "Abhijeet Joglekar" <abhijeet at cs.utah.edu>
To: <ixp1200 at CS.Princeton.EDU>
Sent: Tuesday, February 18, 2003 12:49 PM
Subject: Re: [ixp1200] peth driver question, need help


> Warning: I havent used PETH so I might be totally off on this, but
> I am taking a guess.
> 
> *********
> Looks like you are generating packets faster than the rate at which
> xmt code sends them out and returns the descriptor to the SRAM push/pop
> queue. What is the number of buffers in your freelist? It is around 50
> packets/slots for usual ethernet devices. You dont probably want it bigger
> than that because it can cause long queuing delays for low bandwidth
> links.
> 
> What rate are you generating packets at?
> *********
> 
> -- abhijeet
> 
> On Tue, 18 Feb 2003, huangtao wrote:
> 
> > I have always start the microengine,   I can ping to another ip address, but if the speed is a litter high, peth will drop
> > some packet. this error is occured below:
> >
> > in the peth_start_xmit function of source file peth.c
> >      ....
> >     /* Get a new descriptor where we can write the packet data */
> >     sram_pop(freelist, &descriptor);
> >     descriptor = PETH_DESC_CORETOUENG(descriptor);     ------> this descriptor is 0
> >      ....
> >     PETH_DESC_POSTPOP(descriptor);
> >
> >     /* Sanity check */
> >     if (!PETH_VALID_DESCRIPTOR(descriptor)) {
> >       logMsg("Bad descriptor %x, dropping outgoing packet\n", descriptor);    -----> so have a error message
> >       pethFreeDescriptor(freelist, descriptor);
> >       goto errorAndCleanTXD;                      ---->xmit packet is droped
> >     }
> >      ....
> >
> > who can help me pls.
> >
> > Best Regard
> >
>