hi everyone, I have written my own data collection tool, for custom needs using libpcap for wireless interfaces(2.4,5 GHz) on a router.
I could not find any flag in tcpdump that i can collect only x number of mgmt packets, y number of control packets and the rest data packets. The issue i face is this : When I run two instances of tcpdump on each interface, it has 5-10% cpu usage on the router. When I use my tool written using libpcap: When I run it on one interface (say 2.4 GHz), I get 5-10% CPU usage (output on top), but when I run another instance of the tool on the other interface(5 GHz lets say), both the processes start eating 100% of CPU all the time. Can someone explain this behavior ? I was thinking, if both the process's recv() call was spinning on some shared resource (buffer)/some kernel thread ... but why does that not happen for tcpdump ? I have literally read tcpdump/pcap code before, but I hadn't notice anything special. Can someone help me debug this problem ? - Abhinav _______________________________________________ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
