Re: em0: watchdog timeout ...

On 10/31/07, Mike Tancsa <mike_at_sentex.net> wrote:
> At 06:25 PM 10/31/2007, Jack Vogel wrote:
> > > >
> > > >What if you use MSI?
> > >
> > > How do I enable that ?
> >
> >sysctl hw.pci.enable_msi=1
> >
> >and
> >
> >sysctl hw.pci.enable_msix=1
> >
> >For those that don't know, MSI/X is there in STABLE but off by default.
>
> Thanks,
>          Do I need to do this in /boot/loader.conf or can I set it at
> any time?  Are there any performance hits / boosts to use this method
> instead of the default ?

I have set it after the system booted and it seemed to work.

John could speak more authoritatively since he wrote it, but I have
seen no problem turning em use on whenever. Uh, this means of
course, enabling it and THEN loading the driver, if em is loaded and
you enable the system it will have no effect on em until unload and
reloading it.

John has also said that MSI in 6.X is not as full an implementation as
in 7 but I don't recall what that amounted to.

It means you have a unique unshared interrupt, I have never really had
any performance tests done on MSI vs Legacy so I can't speak to that.

Jack