Hi Luca, As always congratulations. Now one question, its clear just 1 user space application can use this data (unless they cooperate some way). My question is, how about kernel? I mean, this copies the data to user land very fast but is the kernel still able to see that data for things like forwarding or firewalling?
Regards El dom, 21-02-2010 a las 21:15 +0100, Luca Deri escribió: > Dear all, > this is to announce the availability of PF_RING DNA (Direct NIC Access) that > significantly increments performance (up to 80%) when compared with Linux > packet capture and PF_RING (non DNA). > > PF_RING is polling packets from NICs by means of Linux NAPI. This means that > NAPI copies packets from the NIC to the PF_RING circular buffer, and then the > userland application reads packets from ring. In this scenario, there are two > pollers, both the application and NAPI and this results in CPU cycles used > for this polling; the advantage is that PF_RING can distribute incoming > packets to multiple rings (hence multiple applications) simultaneously. > > PF_RING DNA (Direct NIC Access) is a way to map NIC memory and registers to > userland so that packet copy from the NIC to the DMA ring is done by the NIC > NPU (Network Process Unit) and not by NAPI. This results in better > performance as CPU cycles are used uniquely for consuming packets and not for > moving them off the adapter. The drawback is that only one application at > time can open the DMA ring, or in other words that applications in userland > need to talk each other in order to distribute packets. > > In a nutshell if you like flexibility you should use PF_RING, if you want > pure speed PF_RING DNA is the solution. Please note that in DNA mode NAPI > polling does not take place, hence PF_RING features such as reflection and > packet filtering are not supported. > > For more information, please have a look at the PF_RING home page > (http://www.ntop.org/PF_RING.html). As of today DNA support is available only > for Intel 1 Gbit PCI Express (e1000e family) cards. > > Luca > > > --- > > "Debugging is twice as hard as writing the code in the first place. > Therefore, if you write the code as cleverly as possible, you are, by > definition, not smart enough to debug it. - Brian W. Kernighan > > _______________________________________________ > Ntop-misc mailing list > [email protected] > http://listgateway.unipi.it/mailman/listinfo/ntop-misc -- Jaime Nebrera - [email protected] Consultor TI - ENEO Tecnologia SL Pol. PISA - C/ Manufactura 6, P1, 3B Mairena del Aljarafe - 41927 - Sevilla Telf.- 955 60 11 60 / 619 04 55 18 _______________________________________________ Ntop-misc mailing list [email protected] http://listgateway.unipi.it/mailman/listinfo/ntop-misc
