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Date: Wed, 3 Oct 2001 20:23:39 +0200 (CEST)
From: Ingo Molnar <mingo@elte.hu>
Reply-To: <mingo@elte.hu>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: <linux-kernel@vger.kernel.org>
Subject: Re: [announce] [patch] limiting IRQ load, irq-rewrite-2.4.11-B5
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On Wed, 3 Oct 2001, Linus Torvalds wrote:

> Now test it again with the disk interrupt being shared with the
> network card.
>
> Doesn't happen? It sure does. [...]

yes, disk IRQs might be delayed in that case. Without this mechanizm there
is a lockup.

> Which is why I like the NAPI approach.  If somebody overloads my
> network card, my USB camera doesn't stop working.

i agree that NAPI is a better approach. And IRQ overload does not happen
on cards that have hardware-based irq mitigation support already. (and i
should note that those cards will likely perform even faster with NAPI.)

> I don't disagree with your patch as a last resort when all else fails,
> but I _do_ disagree with it as a network load limiter.

okay - i removed those parts already (kpolld) in today's patch. (It
initially was an experiment to prove that this is the only problem we are
facing under such loads.)

	Ingo

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