Subject: Re: irqpoll kernel option hurts performance?
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: xp newbie <xp_newbie@yahoo.com>
Cc: linux-kernel@vger.kernel.org
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Date: Fri, 03 Nov 2006 11:52:04 +0000
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Ar Iau, 2006-11-02 am 21:37 -0800, ysgrifennodd xp newbie:
> specified the "irqpoll" option to boot the installation CD, is the
> system doomed to always work in "IRQ polling mode" (which is much more
> CPU wasteful if I understand this correctly)? Am I really using my
> hardware now in less than optimal manner (like in PIO vs. DMA, for
> example)?

irqpoll has a small impact, how big depends what the box does (on a
gigabit network firewall its bad news, on a typical desktop its not
measurable).

IRQ problems of the form you report can arise from a couple of places -
one is vendors getting IRQ routing tables wrong (suprisingly common),
the other may be a Linux bug.

Checking for a BIOS update may therefore be useful. 

Is this a VIA chipset machine ?

Alan

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