tcpdump mailing list archives
Re: packet drops and zero copy filtering?
From: Guy Harris <guy () alum mit edu>
Date: Sun, 13 Jul 2003 19:17:48 -0700
On Sun, Jul 13, 2003 at 03:32:56PM -0700, Yuchung Cheng wrote:
I also run tcpdump on a busy gigabites link (90MBps) and tcpdump is dropping lots of packets and locking up the cpu, is there any patch for using Linux sendfile(2) to minimize dumping to file overhead for capturing?
Well, that might be an interesting patch, but it wouldn't write out a tcpdump-format file, it'd write out a Linux-format file (and given that at least some of the information in the packet header isn't returned by "recvfrom()" in the buffer, it's returned from elsewhere, it might not even be possible without a *kernel* patch as well).
Or can someone recommend tools for high speed capturing (for Linux)?
Phil Wood's patch to use the memory-mapped capture mechanism: http://public.lanl.gov/cpw/ might help, although it's not zero-copy if you're writing to a file. - This is the TCPDUMP workers list. It is archived at http://www.tcpdump.org/lists/workers/index.html To unsubscribe use mailto:tcpdump-workers-request () tcpdump org?body=unsubscribe
Current thread:
- packet drops and zero copy filtering? Yuchung Cheng (Jul 13)
- Re: packet drops and zero copy filtering? Guy Harris (Jul 13)
- Re: packet drops and zero copy filtering? Ben Greear (Jul 13)
- Re: packet drops and zero copy filtering? Richard Sharpe (Jul 13)
- Re: packet drops and zero copy filtering? Ben Greear (Jul 14)
- Re: packet drops and zero copy filtering? Richard Sharpe (Jul 14)
- Re: packet drops and zero copy filtering? Guy Harris (Jul 14)
- Re: packet drops and zero copy filtering? Loris Degioanni (Jul 14)
- Re: packet drops and zero copy filtering? Ben Greear (Jul 13)
- Re: packet drops and zero copy filtering? Guy Harris (Jul 14)
- Re: packet drops and zero copy filtering? Guy Harris (Jul 13)