Ethereal-dev: Re: [ethereal-dev] High resolution timers

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

Date Index Thread Index Other Months All Mailing Lists
Date Prev Date Next Thread Prev Thread Next
From: Lyle Bickley <lpb@xxxxxxxx>
Date: Tue, 05 Jan 1999 11:53:17 -0800
Christian Brunner wrote:
> 
> Since I'm at writing mails, I want to ask a question, too. Maybe someone
> has an idea.
> 
> I want to generate a constant load on the network, sending out arbitrary
> packets. The problem is, that I have to send out the packets at a fairly
> high rate (especially on fast networks). My first idea was to simply use
> an alarm timer to do this, but under x86-Linux (I don't think other
> systems make to much of a difference here) the kernel timer has a
> resolution of 20ms, which is half an eternity, when I have to send out a
> packet every 50 microsecond.

You might want to look at the high resolution timer used by the SMP
folks (See time.c in arch/i386/kernel).  To use it you have to configure
Linux under "Character Devices" to include "Enhanced Real Time Clock
Support".  The enhanced timer supports microsecond or better ticks.

Lyle
-- 
Lyle P. Bickley  |  Bickley Consulting West Inc.
lpb@xxxxxxxxxxx  |  1697 Grant Road
V 650-428-0621   |  Mountain View, CA 94040
F 650-428-0599   |