Re: [PATCH] x86_32: trim memory by updating e820 v3

From: Gabriel C <nix.or.die@googlemail.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Jesse Barnes <jesse.barnes@intel.com>,
	Mika Fischer <mika.fischer@zoopnet.de>,
	balajirrao@gmail.com, Andi Kleen <andi@firstfloor.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] x86_32: trim memory by updating e820 v3
Date: Mon, 28 Apr 2008 16:15:18 +0200	[thread overview]
Message-ID: <4815DBF6.9010509@googlemail.com> (raw)
In-Reply-To: <20080428135351.GF3973@elte.hu>

Ingo Molnar wrote:
> * Gabriel C <nix.or.die@googlemail.com> wrote:
> 
>>> please try v2 version
>>>
>>> http://lkml.org/lkml/2008/4/28/115
>> Box still won't boot with mtrr_chunk_size=1g but without it is perfect 
>> :)) Thx for your work. I've quick tested some games and 3d things , 
>> all are working with this patch really nice.
> 
> excellent. So just to make sure: this box never had proper graphics 
> under Linux (under no previous kernel), due to the way the BIOS has set 
> up the MTRR's, right?

The box is really new so far I tested 2.6.24* 2.6.25 , linux-next , current git from
which no one worked. And yes is right graphics under Linux didn't worked right without 
patch from http://lkml.org/lkml/2008/4/28/115.

> 
> so fixing up the MTRRs during bootup, no matter how dangerous in theory, 
> is pretty much the best option to get your system to work fine under 
> Linux, with that specific Xorg version?

Yes.

I run :

xorg-server 1.4.0.90-5 ( it has all fixes from server-1.4-branch )
mesa 7.0.2-2
xf86-video-intel 2.3.0-1

Probably I have to replace 2x2G with 2x1G to get it work without this patch but it is something I don't really want to do =)

Also I'm not sure whatever this is an BIOS bug ? I could contact ASUS people if someone tells me what is wrong with the BIOS.

> 
> i think we should still try to make this a non-default option because 
> modern Xorg should not have any need to touch MTRRs. Perhaps a .config 
> dependent on CONFIG_DANGEROUS ;-)

Hmm 1.4.0.90 is not that old , is it ?

> 
> 	Ingo
> 

Gabriel