Problem with MGETHDR

[Eric Norum]

"Smith, Gene" wrote:
> 
> > From: Alexey S. Fadeyev [mailto:alexey at vocord.com]
> 
> > Hi
> >
> > In rxDaemon I alloc memory with MGETHDR and MCLGET for packet arrive
> > but as soon as I begin to work with it -
> > MGETHDR(m,M_WAIT,MT_DATA);
> > MCLGET(m,M_WAIT);
> > m->m_pkthdr.rcvif = ifp; (as in examples)
> > RTEMS tells me
> > RTEMS: Network mbuf space can not be enlarged after
> > rtems_bsdnet_initialize
> > has
> > returned.
> > What's wrong?
> > In driver_attach function I set mtu to 1500.
> > Any ideas?
> >
> > Regards
> > Alexey
> >
> > P.S.
> > Btw - when the mailing-list will be update?
> 
> I see the same rtems panic message but after my system has been only
> listening on a very broadcast intensive ethernet for a random length of
> time.  I can see that the memory for mbufs and clusters can be set in
> networkconfig.h above the default 64k/128k value. However, my question would
> be: Is it typical to have to increase these or does it indicated a deeper
> problem?
> 
> This panic error has only occurred once while listening on the network for
> several hours today.
> 

The default numbers are certainly on the small side, especially if
you're on a network with lots of broadcast traffic.  For most of my
applications I up these sizes by a factor of 4 or so -- but my boards
have 4 or 16 Mbytes of memory respectively, and are controlling a very
large, very expensive, piece of equipment.

-- 
Eric Norum                                 eric at cls.usask.ca
Canadian Light Source                      Phone: (306) 966-6308
University of Saskatchewan                 FAX:   (306) 966-6058
Saskatoon, Canada.