Re: [RFD] CAT user space interface revisited

From: Thomas Gleixner
Date: Fri Nov 20 2015 - 02:54:21 EST


On Thu, 19 Nov 2015, Marcelo Tosatti wrote:
> On Thu, Nov 19, 2015 at 10:09:03AM +0100, Thomas Gleixner wrote:
> > On Wed, 18 Nov 2015, Marcelo Tosatti wrote
> > > Actually, there is a point that is useful: you might want the important
> > > application to share the L3 portion with HW (that HW DMAs into), and
> > > have only the application and the HW use that region.
> > >
> > > So its a good point that controlling the exact position of the reservation
> > > is important.
> >
> > I'm glad you figured that out yourself. :)
> >
> > Thanks,
> >
> > tglx
>
> The HW is a reclaimer of the L3 region shared with HW.
>
> You might want to remove any threads from reclaiming from
> that region.

I might for some threads, but certainly not for those which need to
access DMA buffers. Throwing away 10% of L3 just because you don't
want to deal with it at the interface level is hillarious.

Thanks,

tglx
--
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/