Re: [PATCH 5/5] drm/i915: debugfs entries for [e]LLC

[Ben Widawsky <ben@bwidawsk.net>]

On Tue, Jul 09, 2013 at 11:35:38AM -0700, Chad Versace wrote:
> On 07/04/2013 11:46 AM, Ben Widawsky wrote:
> >On Thu, Jul 04, 2013 at 08:43:58PM +0200, Daniel Vetter wrote:
> >>On Thu, Jul 4, 2013 at 8:40 PM, Ben Widawsky <ben@bwidawsk.net> wrote:
> >>>On Thu, Jul 04, 2013 at 08:14:41PM +0200, Daniel Vetter wrote:
> >>>>On Thu, Jul 04, 2013 at 11:02:07AM -0700, Ben Widawsky wrote:
> >>>>>To make users life a little easier figuring out what they have on their
> >>>>>system.
> >>>>>
> >>>>>Ideally, I'd really like to report LLC size, but it turned out to be a
> >>>>>bit of a pain. Maybe I'll revisit it in the future.
> >>>>>
> >>>>>Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> >>>>
> >>>>I think a getparam for eLLC would be neat, so that usespace can use it to
> >>>>tune working set sizes.
> >>>>-Daniel
> >>>>
> >>>And I assume drop debugfs?
> >>
> >>Yeah, I guess the DRM_INFO message in dmesg should be good enough
> >>then. For userspace's convenience we could even look into exposing the
> >>LLC size with a getparam.
> >>-Daniel
> >>
> >
> >I would like to do this since we have easy access to cpuid. I know Chad
> >really wants it. If you'll accept the patch, I'll write it.
> 
> I really want to know the cache sizes.
> 
> Actually, I didn't expect the kernel to do this for me. So, I've prototyped
> a patch for Mesa to probe the cache sizes with CPUID. If the
> kernel does that for Mesa, then I can likely drop my Mesa patch.
> 

I think if we need to do the work, it makes sense to do it in the kernel
since the other components can easily take advantage of it. I can even
shoehorn it in to the existing LLC param.

-- 
Ben Widawsky, Intel Open Source Technology Center