tcpdump mailing list archives
Re: libpcap capture performance drop
From: Rick Jones <rick.jones2 () hp com>
Date: Fri, 27 May 2011 10:16:41 -0700
On Fri, 2011-05-27 at 14:20 +0200, rixed () happyleptic org wrote:
-[ Mon, May 23, 2011 at 12:38:43AM -0700, Guy Harris ]----On May 23, 2011, at 12:31 AM, rixed () happyleptic org wrote:Which brings the question: how one could find out the MTU of a pcap_handle in order no to set caplen to 65535 ?See pcap-linux.c in the top of the trunk or of the 1.2 branch. (Short answer: SIOCGIFMTU, as in the iface_get_mtu() routine.)-If I understand this code correctly, in the next release of the libpcap if a client program ask for a capture length bigger than the MTU then the size allocated for each frame in the ring buffer will be sized down to avoid wasting space ? If so then I just have to wait for the new libpcap :-)
Is this new libpcap going to be guaranteed that the underlying NIC HW isn't doing Large Receive Offload, or that the tracepoint in the stack is below any stack's attempt to do Generic Receive Offload? rick jones - This is the tcpdump-workers list. Visit https://cod.sandelman.ca/ to unsubscribe.
Current thread:
- Re: libpcap capture performance drop Guy Harris (May 20)
- Re: libpcap capture performance drop rixed (May 23)
- Re: libpcap capture performance drop Guy Harris (May 23)
- Re: libpcap capture performance drop rixed (May 27)
- Re: libpcap capture performance drop Rick Jones (May 27)
- Re: libpcap capture performance drop Guy Harris (May 27)
- Re: libpcap capture performance drop Rick Jones (May 27)
- Re: libpcap capture performance drop Guy Harris (May 27)
- Re: libpcap capture performance drop Guy Harris (May 23)
- Re: libpcap capture performance drop rixed (May 23)
- Re: libpcap capture performance drop Guy Harris (May 27)
- Re: libpcap capture performance drop Ben Greear (May 27)
- Re: libpcap capture performance drop Guy Harris (May 27)
- Re: libpcap capture performance drop Guy Harris (May 23)