On Aug 15, 2010, at 6:15 AM, Doktor Bernd wrote: > thanks for the advice. If I use libpcap 1.1.1 compiled with the > HAVE_PACKET_RING stuff commented out, the my softare performs very well. > Ubuntu currently ships with 1.0.0.6 I think. If I use that version my > application has problems capturing 100 Mbit/s of traffic. If I change to the > custom build version of libpcap then I can capture 1 Gbit/s of traffic and > problem occur only for small packet sizes (<100 Byte).
What happens if you build 1.1.1 with no changes (i.e., with the HAVE_PACKET_RING stuff *not* commented out) and use that version? That's the cleanest test of mmap vs. non-mmap. > Any idea why mmap is slowing everything down? I am using pcap_dispatch to > capture packet by packet. (That means you're not using pcap_next() or pcap_next_ex(), correct?) What are you passing as the second argument to pcap_dispatch()? And how are you measuring the packet loss? Are you using the figures from pcap_stats(), or are you determining in some other fashion that packets weren't captured?- This is the tcpdump-workers list. Visit https://cod.sandelman.ca/ to unsubscribe.
