Re: IRQ affinity vs. MTRRs, was Re: 36 bit MTRRs, Re: test10-pre1 problems on 4-way SuperServer8050

From: Gábor Lénárt (
Date: Thu Oct 12 2000 - 05:19:21 EST

On Thu, Oct 12, 2000 at 12:12:19PM +0200, Boszormenyi Zoltan wrote:
> I came up with an idea. The MTRRs are per-cpu things.
> Ingo Molnar's IRQ affinity code helps binding certain
> IRQ sources to certain CPUs.
> What if the MTRR driver allows per-CPU settings, maybe only on
> uncached areas? Of course the real memory should be cached in
> every CPU to avoid slowdowns. So that if you set that eth0's
> IRQ will be handled by CPU1, the MTRRs of CPU1 will be set
> accordingly, and the other CPUs will not care about eth0,
> so they do not need eth0's MTRR settings.

A little question. Why do we want to bind irq of eth0 to a single CPU ?
imho it will casue slowdown of some situation. Why don't we leave scheduler
to select CPU for processing IRQ ?

- Gabor
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

This archive was generated by hypermail 2b29 : Sun Oct 15 2000 - 21:00:22 EST