From: "H. Peter Anvin" <hpa@zytor.com>
To: Tejun Heo <tj@kernel.org>
Cc: "Ingo Molnar" <mingo@elte.hu>,
"Ahmed S. Darwish" <darwish.07@gmail.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>, X86-ML <x86@kernel.org>,
"Tony Luck" <tony.luck@intel.com>,
"Dave Jones" <davej@redhat.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Randy Dunlap" <rdunlap@xenotime.net>,
"Willy Tarreau" <wtarreau@hera.kernel.org>,
"Willy Tarreau" <w@1wt.eu>,
"Dirk Hohndel" <hohndel@infradead.org>,
Dirk.Hohndel@intel.com, IDE-ML <linux-ide@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Peter Zijlstra" <a.p.zijlstra@chello.nl>,
"Frédéric Weisbecker" <fweisbec@gmail.com>,
"Borislav Petkov" <bp@alien8.de>,
"Arjan van de Ven" <arjan@infradead.org>
Subject: Re: [PATCH 0/2][concept RFC] x86: BIOS-save kernel log to disk upon panic
Date: Tue, 25 Jan 2011 09:33:18 -0800 [thread overview]
Message-ID: <4D3F095E.9000004@zytor.com> (raw)
In-Reply-To: <20110125150834.GD27510@htj.dyndns.org>
On 01/25/2011 07:08 AM, Tejun Heo wrote:
>
> There are holes but writing to them without full knowledge of the
> configuration can be quite dangerous. I don't think it would be
> possible to mass deploy it without manual configuration unless we
> specifically reserve (and maybe mark) it in the filesystem.
>
Reserve and mark in the filesystem is relatively straightforward, except
for btrfs, which doesn't have support for reserved extents. This is a
bit of a shortcoming in btrfs.
>> All in one, a very intriguing idea IMO, and the hardest bits
>> (lowlevel x86 transition) is all implemented already.
Lowlevel x86 transition is not at all the hardest part. It's
detail-oriented but well defined (and, I might add, incompletely
implemented -- 64 bits only, not using facilities we already have); the
*hard* part, and I mean harder by orders of magnitude, is to get the
BIOS to behave sanely without an intervening reboot, *AND* not trash
your data, ever.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2011-01-25 17:37 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-25 13:47 [PATCH 0/2][concept RFC] x86: BIOS-save kernel log to disk upon panic Ahmed S. Darwish
2011-01-25 13:51 ` [PATCH -next 1/2][RFC] x86: Saveoops: Switch to real-mode and call BIOS Ahmed S. Darwish
2011-01-25 17:26 ` H. Peter Anvin
2011-01-25 13:53 ` [PATCH -next 2/2][RFC] x86: Saveoops: Reserve low memory and register code Ahmed S. Darwish
2011-01-25 17:29 ` H. Peter Anvin
2011-01-26 9:04 ` Ahmed S. Darwish
2011-01-25 14:09 ` [PATCH 0/2][concept RFC] x86: BIOS-save kernel log to disk upon panic Ingo Molnar
2011-01-25 15:08 ` Tejun Heo
2011-01-25 17:33 ` H. Peter Anvin [this message]
2011-01-26 11:44 ` Ahmed S. Darwish
2011-02-03 14:36 ` Pavel Machek
2011-02-03 15:28 ` H. Peter Anvin
2011-02-03 17:57 ` Ingo Molnar
2011-02-03 21:07 ` H. Peter Anvin
2011-01-25 15:36 ` Ahmed S. Darwish
2011-01-25 16:02 ` James Bottomley
2011-01-25 17:05 ` Ahmed S. Darwish
2011-01-25 17:20 ` James Bottomley
2011-01-25 22:10 ` Mark Lord
2011-01-25 22:16 ` Randy Dunlap
2011-01-25 22:45 ` Jeff Garzik
2011-01-25 22:58 ` H. Peter Anvin
2011-01-26 0:26 ` Jeff Garzik
2011-01-31 2:59 ` Rusty Russell
2011-01-31 10:45 ` Ingo Molnar
2011-01-25 17:32 ` Tony Luck
2011-01-25 17:36 ` H. Peter Anvin
2011-01-25 19:04 ` Jeff Garzik
2011-01-25 14:49 ` Tejun Heo
2011-01-28 7:59 ` Jan Ceuleers
2011-01-25 20:25 ` Linus Torvalds
[not found] ` <20110126124954.GC24527@laptop>
2011-01-26 23:07 ` Luck, Tony
[not found] ` <20110126231620.GA14807@redhat.com>
[not found] ` <987664A83D2D224EAE907B061CE93D53019438EB02@orsmsx505.amr.corp.intel.com>
[not found] ` <20110126233033.GB14807@redhat.com>
[not found] ` <987664A83D2D224EAE907B061CE93D53019438EBB6@orsmsx505.amr.corp.intel.com>
[not found] ` <4D40F7F1.3020509@zytor.com>
[not found] ` <20110127120039.GD20279@elte.hu>
2011-01-27 18:35 ` Luck, Tony
[not found] ` <4D4197CB.9070201@zytor.com>
[not found] ` <20110127162429.GB26437@elte.hu>
2011-01-27 18:56 ` Luck, Tony
[not found] ` <20110127021338.GA20334@redhat.com>
[not found] ` <4D40F81E.1030009@zytor.com>
[not found] ` <20110127052639.GA16289@laptop>
[not found] ` <m1sjweyeax.fsf@fess.ebiederm.org>
2011-02-02 11:13 ` Ahmed S. Darwish
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