Re: fxp0 generating lots of interrupts

Hi,

On Mon, Mar 08, 2004 at 12:44:48AM +0100, Julian wrote:
> Tony Frank <tfrank_at_optushome.com.au> writes:
> 
> > Hi there,
> >
> > On Sun, Mar 07, 2004 at 10:39:27PM +0100, Julian wrote:
> >> I just replaced my old network adaptor with another one and noticed
> >> that vmstat reports lots of interrupts:
> >> 
> >> vmstat -i | grep fxp
> >> irq11: fxp0                      1532367        394
> >> 
> >> Is this "normal"?
> >
> > I guess that depends what you consider to be 'lots'?
> Compared to my old RealTek-based card.
> 
> > If you are using device polling, then I expect the interrupts to be quite
> > high.
> > If you are not using the interface for any network traffic and it is a 
> > quiet network (ie not much broadcast traffic) then I expect the volume 
> > to be high.
> The 394 was during "activity" of about 10 MBit/s. It's down to 200 at
> the moment and there is almost no network activity at the moment.

Note that my server here is running 4.9-STABLE so the results may not be
suitable to directly compare.

While transferring several gb of data from winxp to freebsd server (samba)
I was getting about 5000kbyte/s sustained throughput and fxp0 stats:

fxp0 -link0 around 4000 int/measurement
fxp0 link0 around 750 int/measurement

"Idle" background is typically under 10 int/measurement

When reading several gb of data from freebsd server with winxp box I
get about 6000kbyte/s and fxp0 int of:

fxp0 -link0 around 2500int/measurement
fxp0 link0 around 2500 int/measurement (expected as this is receive only setting)

I am measuring running 'systat -v' and looking at the values shown after several 
updates.

> > What makes you think you have 'lots' of interupts as opposed to 'normal level' ?
> I've only compared it to my old card. Perhaps I should not have done
> this, as the high interrupt frequency does not impact system
> performance in any noticeable way.

I guess it will depend on how much activity is on the network.
It does not sound unusual to me but I guess it depends on your environment.

Regards,

Tony