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General discussion

irq memory allocation

Sep 9, 2004 10:15AM PDT

I once read how to allocate extra memory to a devices irq, but do not remember how to do it. I do not remember if it was SE or XP but I would like to be able to try it in XP.

Is this a hardware issue or where would be the proper post?

Discussion is locked

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Re: irq memory allocation
Sep 9, 2004 10:38AM PDT

It would make no sense to do so. Here's why. An IRQ when triggered tells the CPU to jump to an address to handle the request. That's just a CPU memory address and in a 32-bit CPU takes 32 bits. Unless we change the CPU design to need more address bits, this would make no sense to attempt to change. In fact, you can't!

When you make such a request, maybe a reference web article about where the idea came from would clarify what you wanted to do.

Bob

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Re: Ok, I can't remember..
Sep 9, 2004 10:46AM PDT

It was something about giving the lan card more memory when it was sharing an irq with another device to improve poor internet performance, and it was for 98 SE.

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Still doesn't make sense
Sep 10, 2004 2:37AM PDT

1) I Would never want to share an IRQ for a lan device.
2) What would be able to share an IRQ with a NIC card and not be interrupted all the time ?

You could quite possibly change the message size - but depending on the Protocol - that is usually worked out in the negotiation phase at start up.

If you can find the article itself - that might help.

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(NT) (NT) Re: If I run across it I'll post it.
Sep 10, 2004 4:14AM PDT
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Doesn't make sense to me either.
Sep 10, 2004 4:19AM PDT

I have designed PCI cards. IRQ sharing is a fact of the PC and if you don't like it, its time to not buy another PC until they redesign the IRQ system.

Can you say "unlikely?"

The bad old days of ISA are finally gone and with each passing year I see the old machines that did have an issue with IRQ routing finally hit the dumpster.

Please research this in depth before you say it is so.

Bob

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Re: irq memory allocation
Sep 11, 2004 4:26AM PDT