Re: [patch] forcedeth: fix the NAPI poll function

From: Ingo Molnar
Date: Tue Oct 16 2007 - 03:50:10 EST



* Jeff Garzik <jeff@xxxxxxxxxx> wrote:

> >FYI, looks good so far, ontop of Linus' latest -git tree.
> >
> >btw., one thing i always found weird about forcedeth is that it
> >generates an extra ~100 irqs per second even when there's no network
> >traffic:
> >
> > 11: 89752 XT-PIC-XT eth0
> > 11: 89854 XT-PIC-XT eth0
> > 11: 89955 XT-PIC-XT eth0
> > 11: 90056 XT-PIC-XT eth0
> > 11: 90157 XT-PIC-XT eth0
> >
> >(irq count snapshot every second). Just in case it's easy to fix ...
>
>
> May I presume that behavior occurs in both mainline and my fe-lock
> branch?

correct.

> That is likely the NIC's timer irq, which is programmed to kick the
> irq handler every so often. DEV_NEED_TIMERIRQ is a starting point, as
> well as "Known bugs" at the top of forcedeth.c, if you're curious.
>
> I'm _betting_ that some of that can be eliminated, but we'll see...

ok. Was just a FYI - you were looking for feedback :-)

Ingo
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