From: Andi Kleen <andi@firstfloor.org>
To: Loic Prylli <loic@myri.com>
Cc: "Andi Kleen" <andi@firstfloor.org>,
"Cédric Augonnet" <cedric.augonnet@gmail.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Andrew Morton" <akpm@osdl.org>,
brice@myri.com, cedric.augonnet@ens-lyon.org
Subject: Re: PAT support for i386 and x86_64
Date: Wed, 8 Aug 2007 12:14:41 +0200 [thread overview]
Message-ID: <20070808101441.GA12861@one.firstfloor.org> (raw)
In-Reply-To: <46B97E39.3020905@myri.com>
> I don't see why we have to worry about cache corruption in the case at
> hand. Write-combining is needed to map io (typically pci-mem regions)
> which are never mapped cachable anywhere, including in the linear map.
If we WC them using PAT then there would be a UC<->WC conflict with
the direct mapping and possibly others. That's already undefined
and not allowed.
After some very bad experiences in the past I'm not going to take
chances on this.
We really need to keep all possible mappings synchronized.
-Andi
next prev parent reply other threads:[~2007-08-08 10:14 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-07 2:03 [PATCH 0/2] PAT support for i386 and x86_64 Cédric Augonnet
2007-08-07 8:30 ` Andi Kleen
2007-08-08 8:26 ` Loic Prylli
2007-08-08 10:14 ` Andi Kleen [this message]
2007-08-08 15:52 ` Cédric Augonnet
[not found] ` <f56c1ba00708080842i1eaa00kef5071d9a1f01f04@mail.gmail.com>
2007-08-08 16:00 ` Andi Kleen
-- strict thread matches above, loose matches on Subject: below --
2007-08-07 12:34 Daniel J Blueman
2007-08-07 14:10 ` Andi Kleen
2007-08-07 15:26 ` Daniel J Blueman
2007-08-07 15:33 ` Andi Kleen
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