svn commit: r238765 - head/sys/dev/e1000

[Jack Vogel]

I have some changes that are needed anyway, I will change this to a
tuneable.

Jack


On Mon, Jul 30, 2012 at 11:45 AM, John Baldwin <jhb at freebsd.org> wrote:

> On Wednesday, July 25, 2012 7:28:15 am Luigi Rizzo wrote:
> > Author: luigi
> > Date: Wed Jul 25 11:28:15 2012
> > New Revision: 238765
> > URL: http://svn.freebsd.org/changeset/base/238765
> >
> > Log:
> >   Use legacy interrupts as a default. This gives up to 10% speedup
> >   when used in qemu (and this driver is for non-PCIe cards,
> >   so probably its largest use is in virtualized environments).
> >
> >   Approved by:        Jack Vogel
> >   MFC after:  3 days
>
> Why not make this a tunable or some such?  You could even have it only use
> the
> legacy handler under qemu easily enough.  There's no reason this has to be
> a
> compile-time option.  This is almost certainly slower on real hardware
> where
> this is important to work around dubious Intel Host-PCI bridges that
> result in
> aliased USB interrupts for every em(4) interrupt.
>
> --
> John Baldwin
>