From: Borislav Petkov <bp@alien8.de>
To: Andreas Werner <wernerandy@gmx.de>
Cc: Ingo Molnar <mingo@kernel.org>,
tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] X86: MM: Add PAT Type write-through in combination with mtrr
Date: Mon, 28 Oct 2013 12:45:41 +0100 [thread overview]
Message-ID: <20131028114541.GI4314@pd.tnic> (raw)
In-Reply-To: <20131028112505.GD2278@thinkpad.fritz.box>
Drop Dave's stale mail address.
On Mon, Oct 28, 2013 at 12:25:05PM +0100, Andreas Werner wrote:
> > but you end up doing
> >
> > PAT=Write-Back + MTRR=Write-Through = Effective Memory of Write-Back
> >
> No the effective memory type is WT, check out the Intel document with the
> table of Effective memory type combinations.
You need to read what I'm saying more carefully.
> Yes but, there is no way in the kernel to mark a memory WT,
That doesn't mean you can return _PAGE_CACHE_WB for MTRR_TYPE_WRTHROUGH.
The correct thing to do, IMHO, would be to set the PWT bit in the PTEs
of those pages comprising your buffer.
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
next prev parent reply other threads:[~2013-10-28 11:45 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-27 12:55 Andreas Werner
2013-10-27 13:34 ` Borislav Petkov
2013-10-27 16:51 ` Andreas Werner
2013-10-27 17:31 ` Borislav Petkov
2013-10-27 17:56 ` Andreas Werner
2013-10-27 19:01 ` Borislav Petkov
2013-10-28 6:29 ` Andreas Werner
2013-10-28 10:17 ` Ingo Molnar
2013-10-28 10:29 ` Borislav Petkov
2013-10-28 10:31 ` Ingo Molnar
2013-10-28 10:44 ` Borislav Petkov
2013-10-28 10:45 ` Andreas Werner
2013-10-28 10:51 ` Ingo Molnar
2013-10-28 10:53 ` H. Peter Anvin
2013-10-28 11:02 ` Andreas Werner
2013-10-28 10:31 ` H. Peter Anvin
2013-10-28 10:34 ` Andreas Werner
2013-10-28 10:57 ` Borislav Petkov
2013-10-28 11:25 ` Andreas Werner
2013-10-28 11:45 ` Borislav Petkov [this message]
2013-10-28 12:03 ` Andreas Werner
2013-10-28 13:58 ` Borislav Petkov
2013-10-28 14:19 ` Andreas Werner
-- strict thread matches above, loose matches on Subject: below --
2013-08-25 7:01 Andreas Werner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20131028114541.GI4314@pd.tnic \
--to=bp@alien8.de \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=wernerandy@gmx.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome