(try again to send to ecos) On 07/20/2011 09:15 PM, Stanislav Meduna wrote: > > Hi, > > I am quite reproducibly able to produce > > eth_recv out of MBUFs > > in the FreeBSD stack. The setup is two incoming TCP connections > sending data, a UDP socket sending data, pinging the device, > closing and reopening the TCP connections a few times and > to pull and put back the ethernet cable. > Be carefull: the eCos freeBSD stack has no timeouts on TCP connections I believe, but often the PC stack has! So the eCos TCP session stays alive, but the PC (used to test) stack shuts down the TCP connection when the cable breaks (after a timeout, or it can also detect the cable fault). And the TCPs are out of sync (something like that), and then it uses a lot of sockets, and indeed (as in your next mail) the timeouts are very big to free sockets. If that is your problem, I can ask my college: he recompiled ecos to change the minute timeout to seconds. > > > The device then never recovers. The partner sends ARP requests > with no response from eCos, as there is no mbuf to accept them. > The eCos never send anything. eth_drv_tickle_devices runs, but > finds IF_IS_EMPTY(&ifp->if_snd) true and never touches > the interface. Maybe it wants to ARP first, but was unable > to send the request - I don't know. Unless I am blind > I am caling tx_done for every packet I got into send > (but I am going to double-check this). > > The mbufs as shown by cyg_net_show_mbufs are full of DATA > with short size (60 or 64) and flags 2 (M_PKTHDR). > > Anyone has seen something like that? I am not very familiar > with the TCP/IP stacks in general - so it is quite problematic > for me to debug something there. Are there some constraints > of the "mbuf space has to be larger than tcp window of active > connections" type or something like that? > > I am reluctant to try to "fix" it enlarging the space for mbufs, > as I think this should never happen regardless of mbufs and I am > also on a quite memory-constrained device where every 100 kB > matter. > With a slow device and big burst of data, I had to increase the space for mbufs. I have had some problems with segmented data (using IP packets of > 1518B(-header sizes)), but I believe the freeBSD stack is OK.
Better use lwIP on memory-constrained devices. And lwIP is more actively maintained.. Success, Jürgen > > > Thanks for any hints > -- > Stano > > -- > Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos > and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss > -- Jürgen Lambrecht R&D Associate Tel: +32 (0)51 303045 Fax: +32 (0)51 310670 http://www.televic-rail.com Televic Rail NV - Leo Bekaertlaan 1 - 8870 Izegem - Belgium Company number 0825.539.581 - RPR Kortrijk -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
