Re: My vote against eepro* removal

From: Evgeniy Polyakov
Date: Fri Jan 20 2006 - 06:04:46 EST


On Fri, Jan 20, 2006 at 11:19:20AM +0100, kus Kusche Klaus (kus@xxxxxxxx) wrote:
> From: Evgeniy Polyakov
> > Each MDIO read can take upto 2 msecs (!) and at least 20
> > usecs in e100,
> > and this runs in timer handler.
> > Concider attaching (only compile tested) patch which moves
> > e100 watchdog
> > into workqueue.
>
> Hmmm, I don't think moving it around is worth the trouble
> (nevertheless, I will test later if I find time).
>
> For a full preemption kernel, both timer code and workqueue code
> are executed in a thread of their own. If I know that there is a
> 500 us piece of code in either of them, I have to adjust the prio
> of the corresponding thread (and all others) accordingly anyway.
>
> For a non-full preemption kernel, your patch moves the 500 us
> piece of code from kernel to thread context, so it really
> improves things. But is 500 us something to worry about in a
> non-full preemption kernel?

In the worst case it will be milliseconds, which is not very nice
timeout for timer handler...

P.S. above patch works without problems with my e100 card.

> --
> Klaus Kusche (Software Development - Control Systems)
> KEBA AG Gewerbepark Urfahr, A-4041 Linz, Austria (Europe)
> Tel: +43 / 732 / 7090-3120 Fax: +43 / 732 / 7090-6301
> E-Mail: kus@xxxxxxxx WWW: www.keba.com

--
Evgeniy Polyakov
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