From: "Yinghai Lu" <yhlu.kernel@gmail.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Gabriel C" <nix.or.die@googlemail.com>,
"Andi Kleen" <andi@firstfloor.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Ingo Molnar" <mingo@elte.hu>, "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
Subject: Re: [PATCH] x86_32: trim memory by updating e820 v3
Date: Mon, 28 Apr 2008 16:16:26 -0700 [thread overview]
Message-ID: <86802c440804281616t6a62cb74h430b4ca598d101bc@mail.gmail.com> (raw)
In-Reply-To: <m17ieh4zuo.fsf@frodo.ebiederm.org>
On Mon, Apr 28, 2008 at 11:07 AM, Eric W. Biederman
<ebiederm@xmission.com> wrote:
> "Yinghai Lu" <yhlu.kernel@gmail.com> writes:
>
> > On Sat, Apr 26, 2008 at 5:56 AM, Gabriel C <nix.or.die@googlemail.com> wrote:
>
>
> > another continuous MTRR mapping.
> >
> > several months ago, we were talking about modifying MTRR. but Eric
> > said that is not safe because acpi and smi...
>
> I think it was Andi who spotted that originally, and yes I do think it
> is a pretty horrific failure mode. Reprogramming the MTRRs requires
> full knowledge of the hardware and what is going on that we don't
> always have. PAT support has just been merged, and using that only
> requires knowledge about the region whose attributes we intend to change.
>
> So lets concentrate on PAT to solve contiguous MTRR region problems.
>
> We can upgrade UC to WC with pat. As well as demote WB to UC or WC.
> So for those regions we know about we should be in good shape.
>
> In a slightly related vein. Trimming the memory we consider usable by
> looking at MTRRs and if a region is not WB not considering it RAM
> sounds like a very reasonable work around for one class of BIOS bugs.
yeah, i will look at to loop the ram region array instead of checking
highest_pfn only...
YH
next prev parent reply other threads:[~2008-04-28 23:16 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-20 4:45 [PATCH] x86: disable_mtrr_trim only need for x86_64 Yinghai Lu
2008-01-20 5:37 ` H. Peter Anvin
2008-01-20 6:55 ` Yinghai Lu
2008-01-20 8:17 ` [PATCH] x86_64: update e820 instead of updating end_pfn Yinghai Lu
2008-01-20 9:20 ` Ingo Molnar
2008-01-20 15:08 ` Andi Kleen
2008-01-21 5:40 ` [PATCH] x86_64: update e820 instead of updating end_pfn v2 Yinghai Lu
2008-01-21 5:44 ` [PATCH] x86_32: trim memory by updating e820 Yinghai Lu
2008-01-21 5:58 ` [PATCH] x86_64: update e820 instead of updating end_pfn v2 Andi Kleen
2008-01-21 6:05 ` Harvey Harrison
2008-01-21 6:08 ` Andi Kleen
2008-01-21 6:14 ` Li Zefan
2008-01-21 6:57 ` [PATCH] x86_64: check if Tom2 is enabled Yinghai Lu
2008-01-21 17:24 ` Cyrill Gorcunov
2008-01-21 17:39 ` H. Peter Anvin
2008-01-21 17:49 ` Cyrill Gorcunov
2008-01-21 18:03 ` Andi Kleen
2008-01-21 18:09 ` Cyrill Gorcunov
2008-01-21 18:15 ` H. Peter Anvin
2008-01-21 18:46 ` Andi Kleen
2008-01-21 0:00 ` [PATCH] x86_64: update e820 instead of updating end_pfn Yinghai Lu
[not found] ` <200801202255.02645.yinghai.lu@sun.com>
[not found] ` <200801202255.58642.yinghai.lu@sun.com>
2008-01-21 6:56 ` [PATCH] x86_32: trim memory by updating e820 v2 Yinghai Lu
2008-01-21 16:30 ` Jesse Barnes
2008-01-21 19:14 ` Justin Piszcz
2008-01-21 20:09 ` Yinghai Lu
2008-01-21 21:37 ` Justin Piszcz
2008-01-23 3:50 ` Yinghai Lu
2008-01-26 0:01 ` Justin Piszcz
2008-01-26 0:16 ` Yinghai Lu
2008-01-26 0:37 ` Justin Piszcz
2008-01-28 15:09 ` Ingo Molnar
2008-01-28 18:07 ` Justin Piszcz
2008-01-22 16:51 ` Ingo Molnar
2008-01-23 0:23 ` [PATCH] x86_32: trim memory by updating e820 v3 Yinghai Lu
2008-04-26 10:56 ` Andrew Morton
2008-04-26 12:56 ` Gabriel C
2008-04-27 1:05 ` Yinghai Lu
2008-04-28 18:07 ` Eric W. Biederman
2008-04-28 23:16 ` Yinghai Lu [this message]
2008-04-29 10:31 ` Ingo Molnar
2008-04-29 17:29 ` Eric W. Biederman
2008-04-29 18:40 ` Yinghai Lu
2008-04-29 19:19 ` Eric W. Biederman
2008-04-29 19:44 ` Yinghai Lu
2008-04-29 20:02 ` Eric W. Biederman
2008-04-28 6:44 ` Yinghai Lu
2008-04-28 9:18 ` Gabriel C
2008-04-28 9:34 ` Yinghai Lu
2008-04-28 9:54 ` Gabriel C
2008-04-28 10:03 ` Gabriel C
2008-04-28 10:07 ` Mika Fischer
2008-04-28 19:03 ` Yinghai Lu
2008-04-28 13:53 ` Ingo Molnar
2008-04-28 14:11 ` Mika Fischer
2008-04-28 14:24 ` Gabriel C
2008-04-28 19:06 ` Yinghai Lu
2008-04-28 19:38 ` Gabriel C
2008-04-28 20:45 ` Gabriel C
2008-04-28 21:19 ` Gabriel C
2008-04-28 22:03 ` Yinghai Lu
2008-04-28 22:56 ` Gabriel C
2008-04-28 23:23 ` Yinghai Lu
2008-04-29 1:05 ` Gabriel C
2008-04-29 2:41 ` Yinghai Lu
2008-04-29 10:34 ` Ingo Molnar
2008-04-29 10:42 ` Yinghai Lu
2008-04-28 19:08 ` Yinghai Lu
2008-04-28 19:46 ` Gabriel C
2008-04-28 14:15 ` Gabriel C
2008-04-28 16:09 ` Jesse Barnes
2008-04-28 16:31 ` Mika Fischer
2008-04-28 16:55 ` Jesse Barnes
2008-04-29 10:37 ` Ingo Molnar
2008-04-29 12:40 ` Andrew Morton
2008-04-29 15:52 ` Jesse Barnes
2008-04-29 22:03 ` [patch] PCI: export resource_wc in pci sysfs Ingo Molnar
2008-04-29 22:24 ` Andrew Morton
2008-04-27 0:57 ` [PATCH] x86_32: trim memory by updating e820 v3 Yinghai Lu
2008-04-27 8:21 ` Mika Fischer
2008-04-27 1:22 ` Yinghai Lu
2008-04-27 8:29 ` Mika Fischer
2008-04-28 6:50 ` Yinghai Lu
2008-04-28 8:38 ` Mika Fischer
2008-04-28 9:09 ` Yinghai Lu
2008-04-28 9:44 ` Mika Fischer
2008-04-28 9:58 ` Gabriel C
2008-01-21 6:57 ` [PATCH] x86_64: update e820 instead of updating end_pfn v3 Yinghai Lu
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