Re: jitter bursts

[Michael Olbrich <m.olbrich@pengutronix.de>]

On Wed, Sep 05, 2007 at 02:06:36PM +0530, Girish kathalagiri wrote:
> > Unfortunately not but it did get me on the right track. The problem is
> > caused by the e100_watchdog function. As far as I can tell e100_watchdog
> > is called from a timer queue and therefore runs with the priority of
> > that thread. And while I set higher priorities for softirq-net-rx and
> > the application I missed the thread for the hardware interrupt of the
> > network interface. So whenever a packet arived while e100_watchdog was
> > running it got delayed. The periodic pattern is a result of this and
> > speed difference of sender and receiver clocks.
> > The jitter is now <50us but still with some periodic patterns. So I'll
> > need to investigate further.
> >
> There was some discussion going on this issue on netdev ....
> The below link might help you.
> http://www.nabble.com/Re%3A-My-vote-against-eepro*-removal-t954330.html#a2532617

Yes that's exactly the issue I've been experiencing. Thanks for the
link.

michael

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