From owner-freebsd-hackers@FreeBSD.ORG  Sat Apr 24 11:14:10 2004
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Date: Sat, 24 Apr 2004 13:14:26 -0500 (CDT)
From: Mike Silbersack <silby@silby.com>
To: GiZmen <gizmen@blurp.one.pl>
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cc: freebsd-hackers@freebsd.org
Subject: Re: device pooling and high interrupts
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On Sat, 24 Apr 2004, GiZmen wrote:

> Hello,
>
> I am runnign freebsd 5.2.1 on 386 arch with two rl lan cards. My mainboard
> is on VIA KT 266A with AMD athlon 1.1.
> I read man polling and i have HZ=1000. My problem is that when i set up
> sysctl variable kern.polling.enable=1 my interrupts greatly increase.
> When my system is idle and indicate 0-1% interrupts with out polling.
> and when i turn on polling interrupts goes up to about 20% on idle system.
> Is it normal ? I never before use polling and i  dont know that i have
> something bad in my system ?
>
> Can somebody explain me this ?
>
> thx
> --
> Best Regards:
> 		GiZmen

Ruslan can probably jump in and give you a better explanation than I can,
but I'll try to provide a quick answer.  In short, the rl cards + driver
are not well suited to polling and will not work well with it enabled.
Support for polling on rl may in fact be removed as a result of this.

Mike "Silby" Silbersack