Profiling ipfw2 performance

Luigi Rizzo rizzo at icir.org
Thu Jul 24 15:57:50 PDT 2003


On Thu, Jul 24, 2003 at 06:03:25PM -0400, Eric W. Bates wrote:
> Can someone please point me to a method for measuring the packet lag between interfaces when using ipfw and/or ipfw2?

in RELENG_4, i386 kernels you can add the option

	options	KERN_TIMESTAMP

which then allows you to use the TSTMP() macros (defined and
documented in /sys/i386/include/param.h) to record timestamps
using the TSC register, and export the readings to userland
using a sysctl.
This way you can get some reasonable numbers in a non-intrusive way.

	cheers
	luigi

> Thanks.
> 
> Eric W. Bates
> ericx at vineyard.net
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