linux-kernel - Re: [PATCH] x86: mtrr cleanup for converting continuous to discrete

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Date:	Thu, 01 May 2008 14:09:04 +0200
From:	Mika Fischer <mika.fischer@...pnet.de>
To:	yhlu.kernel@...il.com
CC:	Andrew Morton <akpm@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>, "H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Gabriel C <nix.or.die@...glemail.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86: mtrr cleanup for converting continuous to discrete
 - auto detect

Yinghai Lu schrieb:
> loop mtrr chunk_size and gran_size from 1M to 2G to find out optimal value.
> 
> so user don't need to add mtrr_chunk_size and mtrr_gran_size, 
> 
> if optimal value is not found, print out all list to help select less optimal
> value.
> 
> add mtrr_spare_reg_nr= so user could set 2 instead of 1, if the card need more entries.

On my system x86-latest + this patch and using no boot options gives me
this /proc/mtrr:
reg00: base=0x00000000 (   0MB), size=2048MB: write-back, count=1
reg01: base=0x80000000 (2048MB), size= 512MB: write-back, count=1
reg02: base=0xa0000000 (2560MB), size= 256MB: write-back, count=1
reg03: base=0xb0000000 (2816MB), size= 256MB: write-back, count=1
reg04: base=0xbf700000 (3063MB), size=   1MB: uncachable, count=1
reg05: base=0xbf800000 (3064MB), size=   8MB: uncachable, count=1
reg06: base=0x100000000 (4096MB), size=1024MB: write-back, count=1

Which is OK. It could probably collapse reg01-reg03 into one but that's
a minor issue (for me at least, there are probably cases where
collapsing them might save the user from having to specify the
mtrr_spare_reg_nr boot option).

In any case it works fine here. dmesg is attached.

Let me know if there's anything else I should test!

And thanks a lot for all your work, Yinghai! :)

Regards,
 Mika

View attachment "dmesg-2.6.25-x86-latest.git-06791-gd269f9f-dirty.txt" of type "text/plain" (31405 bytes)