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From: Andi Kleen <ak@suse.de>
To: John Fusco <fusco_john@yahoo.com>
Cc: linux-mm@kvack.org
Subject: Re: Making PCI Memory Cachable
Date: Wed, 6 Dec 2006 23:16:27 +0100	[thread overview]
Message-ID: <200612062316.27898.ak@suse.de> (raw)
In-Reply-To: <456C4182.4020302@yahoo.com>

On Tuesday 28 November 2006 15:02, John Fusco wrote:
> I have numerous custom PCI devices that implement SRAM or DRAM on the 
> PCI bus. I would like to explore making this memory cachable in the 
> hopes that writes to memory can be done from user space and will be done 
> in bursts rather than single cycles.

You want write combining, not cacheable. The only way to do 
this currently is to set a MTRR. See Documentation/mtrr.txt 
by default.

>     b) The memory is cachable, but the chipset is throttling the bursts

The normal cache coherency protocol doesn't work over PCI

-Andi

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  reply	other threads:[~2006-12-06 22:16 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-11-28 14:02 Making PCI Memory Cachable John Fusco
2006-12-06 22:16 ` Andi Kleen [this message]
  -- strict thread matches above, loose matches on Subject: below --
2006-12-09 14:33 John Fusco
2006-12-09 21:36 ` Andi Kleen

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