Paal, no, it's not possible to increase the priority of the WinPcap driver. Actually, changing the priority is a concept that doesn't make a lot of sense when talking about drivrs (the packet-capture part of the winpcap driver runs at DPC level, and therefore has higher priority than any other process of the machine), and in every case playing with priorities rarely improves things in these cases. Moving processing in the kernel is sometimes a very good solution (we have used it for our "kernel-level statistics"), but you really have to know what you're doing if you want to avoid months of nightmares. As for easy things to do: - make tests with different cards and NIC drivers: some are remarkably better than others - make sure that the bottleneck is not your application. WinPcap can be as fast as light, and it can have huge buffers, but if your application is slow the buffers will become full and you'll see drops - try to play with mintocopy to minimize the number of context switches
Loris > > We are working on a processing system which uses UDP to > receive raw data. The burst data rate is about 325 MBit/sec > and the packet rate is about 28500 packets/sec. Our challenge > is to receive these data without loosing anything (or as > little as possible). We are using WinPcap 3.1 beta 2 and our > software is written in VS2003/C++. Ther kernel buffer has > been increased to 50 Mbyte. The computer is a 3.2 GHz dual > Xeon running Win XP Prof. Data is received in bursts of up to 0,5 sec. > > Our experience so far is that we loose about 3-5% when we do > simple processing parallell to data reception. The data > receiver is running in a separate thread and I have tried to > increase the priority, but this did not make a large improvement. > > When only receiving data and not doing anything else I am > able to receive almost 100% of the data. This, however, is > not a good solution for us, as we are trying to make a close > to realtime processing system. > > My question is: is it possible to recompile the WinPcap > kernel driver so that the driver gets a higher priority? Or > can anyone suggest a good way to receive data without loss > and do processing at the same time? I have also been thinking > of moving some of our first-line processing into the > kernel-driver. Has anyone tried that? > > Best regards, > > Paal > > ================================================================== This is the WinPcap users list. It is archived at http://www.mail-archive.com/[email protected]/ To unsubscribe use mailto: [EMAIL PROTECTED] ==================================================================
