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Date: Wed, 3 Jul 2002 14:35:54 -0400 (EDT)
From: "Richard B. Johnson" <root@chaos.analogic.com>
Reply-To: root@chaos.analogic.com
To: Xinwen - Fu <xinwenfu@cs.tamu.edu>
cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: kernel timers vs network card interrupt
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On Wed, 3 Jul 2002, Xinwen - Fu wrote:

> Hi, all,
> 	I'm curious that if a network card interrupt happens at the same
> time as the kernel timer expires, what will happen?
> 
> 	It's said the kernel timer is guaranteed accurate. But if
> interrupts are not masked off, the network interrupt also should get
> response when a kernel timer expires. So I don't know who will preempt
> who.
> 
> 	Thanks for information!
> 
> Xinwen Fu

The highest priority interrupt will get serviced first. It's the timer.
Interrupts are serviced in priority-order. Hardware "remembers" which
ones are pending so none are lost if some driver doesn't do something
stupid.

Cheers,
Dick Johnson

Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).

                 Windows-2000/Professional isn't.

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