Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt

Maciej W. Rozycki
2005-07-18T10:47:09Z

On Fri, 15 Jul 2005, Andi Kleen wrote:

> > That's like scratching your left ear with your right hand -- broadcasting
> > that external timer interrupt in the first place is more straightforward.
> > If you want to exclude CPUs from the list of receivers, just use the
> > logical destination mode appropriately.
>
> The problem with that is that it would need regular synchronizations
> of all CPUs to coordinate this. Not good for scalability and I
> believe the fundamentally wrong way to do this.

What to you mean by "regular synchronizations of all CPUs?" And how is a
broadcasted external timer interrupt different from a unicasted one
redistributed further via an all-but-self IPI, except from removing an
unnecessary burden from the CPU targeted by the unicast interrupt?

Maciej