On Fri, Jul 27, 2007 at 08:51:07PM +0200, M. Koehrer wrote: > Hi, > > > What is your real-time requirement? What's the response time upper > > bound? I agree with the people who say this may not be right way to go. > I want to close a control loop. The faster it is the better it is... > Well, to tell concrete numbers, I want to have a response within 300 microseconds. > The request and the response amount of data is about 250 byte UDP > data each (100 MBit full duplex). > > Currently, I am using rtnet (http://www.rtnet.org) and the Xenomai real time framework > for Linux. This works fine. > The drawback of this approach is that rtnet supports > only a limited number of support network adapters. (Special network drivers > are required). > And the preempt patch seems to be closer to standard Linux than a > a Xenomai patched kernel. > One major problem is that shared interrupts do not really work smoothly with Xenomai... > My goal is to replace the Xenomai/rtnet combination with just the kernel-preempt patch. > Thats all well and good, but the preempt patch isn't going to provide the cap on network latency that you're after. I would invest your time in developing drivers for those network cards that you want supported under rtnet. Regards Neil > > > > > For this I have a separate network adapter in my PC that is used > > > solely for this UDP Ethernet traffic. > > > However, I think all Ethernet traffic is be handled by > > > the soft IRQ threads [softirq-net-rx] [softirq-net-tx] but I do > > > not see a way to do real time networking via one of the network adapters. > > > > > > How can I get this UDP networking real time capable? > > > > Regards > > Mathias > > -- > Mathias Koehrer > mathias_koehrer@xxxxxxxx > > > Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren > ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT FÜR ALLE NEUEINSTEIGER > Jetzt bei Arcor: günstig und schnell mit DSL - das All-Inclusive-Paket > für clevere Doppel-Sparer, nur 34,95 ? inkl. DSL- und ISDN-Grundgebühr! > http://www.arcor.de/rd/emf-dsl-2 > - > To unsubscribe from this list: send the line "unsubscribe linux-net" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- /*************************************************** *Neil Horman *Software Engineer *Red Hat, Inc. *nhorman@xxxxxxxxxxxxx *gpg keyid: 1024D / 0x92A74FA1 *http://pgp.mit.edu ***************************************************/ - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
