mtrr setup?

[Net Llama!]

On Fri, 10 Jan 2003, David A. Bandel wrote:
> On Thu, 9 Jan 2003 11:56:35 -0500
> begin  Douglas J Hunley <doug at linux-sxs.org> spewed forth:
>
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > David A. Bandel spewed electrons into the ether that resembled:
> > > > reg00: base=0x00000000 ( 0MB), size=2048MB; write-back, count=1
> > >
> > > you have 2Gb of memory?
> >
> > yep :)
> >
> > > reg00: base=0x00000000 (   0MB), size= 256MB: write-back, count=1
> > > reg01: base=0xe4000000 (3648MB), size=  64MB: write-combining, count=1
> > > reg02: base=0xdc000000 (3520MB), size=   4MB: write-combining, count=1
> > >
> > > IIRC, you can only have one write-back entry, the rest will be
> > > write-combining.  Do you have other entries?  Those others are the
> > > ones
> >
> > what I pasted is the only entry
>
> Then that is definitely non-optimal.  But your X driver for your video
> card should be setting these parameters.  The reg01 entry above is my PCI
> host bridge (entry from /proc/iomem):
> e4000000-e47fffff : PCI device 1106:3112 (VIA Technologies, Inc.)
>
> and from /proc/pci:
>   Bus  0, device   0, function  0:
>     Host bridge: PCI device 1106:3112 (VIA Technologies, Inc.) (rev 0).
>       Master Capable.  Latency=8.
>       Prefetchable 32 bit memory at 0xe4000000 [0xe47fffff].
>
> Not sure what the dc000000 entry is, but since my video card (onboard) is
> 4Mb, that should be it.  But these are all set up by drivers that know how
> to use mtrr.  The docs suggest that that's what supposed to happen, so I
> haven't exactly worried about it before since it "looks" right.
>
> If you don't have an entry that seems to match your video card's memory,
> it's almost certainly not optimized.  What version of X are you running?
> Perhaps you need to upgrade?  Or maybe a quick note to the driver's author
> is in line?

What Doug didn't mention is that he's seeing this on a 1U rackmount
server, that has an onboard ATI RageXP chipset.  Not sure how much that
matters, however i was always of the belief that you shouldn't be running
X on a rackmount server unless something that the server was serving
required X.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Lonni J Friedman				netllama at linux-sxs.org
Linux Step-by-step & TyGeMo		     http://netllama.ipfox.com