Re: [RFC 0/4] dynamically allocate arch specific system vectors

[H. Peter Anvin]

Eric W. Biederman wrote:
> > It is one vector for each cpu.
> >
> > It is more efficient for software if the vector # is the same for all cpus
> Why?  Especially in terms of irq counting that would seem to lead to cache
> line conflicts.
>
> > but the software/hardware can support a unique vector for each cpu. This
> > assumes, of course, that the driver can determine the irq->vector mapping for
> > each cpu.
>
> That sounds like you have a non-standard MSI-X vector.  You certainly have all of
> the same properties.  At which point create_irq() sounds like what you want.
>
> One irq per cpu, per device.
>
> It is the trend.  Don't worry all of the high performance drivers are doing it.
> That is the path that will be optimized.

In particular, it's just another interrupt type.  We already have quite 
a few of those, from XT-PIC to the various IOAPIC ones, to MSI and MSI-X.

Just treating these as variants of MSI seems to me to make most sense, too.

	-hpa

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/