From: Eric Piel <eric.piel@tremplin-utc.net>
To: Pavel Machek <pavel@ucw.cz>
Cc: Dave Hansen <haveblue@us.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Tilman Schmidt <tilman@imap.cc>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, Thomas Renninger <trenn@suse.de>,
Len Brown <len.brown@intel.com>,
Christoph Hellwig <hch@infradead.org>,
Markus Gaugusch <dsdt@gaugusch.at>,
linux-acpi@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>,
Arjan van de Ven <arjanv@redhat.com>,
Eric Biederman <ebiederm@xmission.com>
Subject: Re: [2.6.25-rc5-mm1] BUG: spinlock bad magic early during boot
Date: Mon, 24 Mar 2008 18:05:14 +0100 [thread overview]
Message-ID: <47E7DF4A.4090007@tremplin-utc.net> (raw)
In-Reply-To: <20080324160333.GD4069@atrey.karlin.mff.cuni.cz>
Pavel Machek wrote:
> Hi!
>> Can we use kexec for this? Let's say you get as far in boot as the
>> initrd and realize that you're running on one of these screwed up
>> systems. Can you stick the new DSDT somewhere known (and safe) in
>> memory, and kexec yourself back to the beginning of the kernel boot?
>>
>> When you boot up the second time, you have the new, shiny DSDT there
>> which is, of course, used instead of the bogus BIOS one.
>>
>> It costs you some bootup time, but we're talking about working around
>> really busted hardware here.
>
> Hmmm. I guess we should turn off acpi mode, kexec, turn on acpi mode
> with new dsdt.
>
> Turning off acpi is not exactly easy, but specs describe how to do
> it...
Why do you think it's necessary to turn off acpi mode? What will not
work if we keep it on all the time?
BTW, let me summarize my understanding of the kexec approach:
* the userspace write the new DSDT (cat my-dsdt-image >
/sys/firmware/acpi/tables/DSDT)
* the kernel don't use this DSDT directly but keeps it somewhere warm
and fuzzy in the RAM
* userspace does a kexec
* the new kernel boots and at some (early) point, dsdt_override() is
called. It detects that the special place in the RAM for a new DSDT is
used. It provides this pointer to ACPI as the new place to read the DSDT.
Dave, am I correctly understanding the scenario you had in mind?
I have pratically no knowledge of kexec. Is there a documented way to
pass big chunk of data from one kernel to another one? How can I do that?
Eric
next prev parent reply other threads:[~2008-03-24 17:05 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-11 8:14 2.6.25-rc5-mm1 Andrew Morton
2008-03-11 10:16 ` [Build Faliure] 2.6.25-rc5-mm1 build fails Kamalesh Babulal
2008-03-11 10:56 ` Edward Shishkin
2008-03-11 12:55 ` [Build Failure] 2.6.25-rc5-mm1 Build fails with allmodconfig probe_4drives undefined Kamalesh Babulal
2008-03-11 17:41 ` Andrew Morton
2008-03-11 19:35 ` Bartlomiej Zolnierkiewicz
2008-03-11 18:19 ` Andrew Morton
2008-03-11 19:36 ` Bartlomiej Zolnierkiewicz
2008-03-11 17:09 ` 2.6.25-rc5-mm1 (paravirt/vsmp/no PCI) Randy Dunlap
2008-03-11 18:18 ` Jeremy Fitzhardinge
2008-03-12 0:10 ` Ravikiran G Thirumalai
2008-03-12 1:42 ` Randy Dunlap
2008-03-12 1:51 ` Jeremy Fitzhardinge
2008-03-12 7:14 ` Ingo Molnar
2008-03-11 20:23 ` 2.6.25-rc5-mm1 serge
2008-03-11 20:39 ` 2.6.25-rc5-mm1 Andrew Morton
2008-03-12 19:33 ` 2.6.25-rc5-mm1 Torsten Kaiser
2008-03-12 19:44 ` 2.6.25-rc5-mm1 Andrew Morton
2008-03-12 20:01 ` 2.6.25-rc5-mm1 Torsten Kaiser
2008-03-13 22:05 ` 2.6.25-rc5-mm1 Torsten Kaiser
2008-03-13 22:35 ` 2.6.25-rc5-mm1 Andrew Morton
2008-03-13 23:10 ` 2.6.25-rc5-mm1 Badari Pulavarty
2008-03-21 12:12 ` 2.6.25-rc5-mm1 Ingo Molnar
2008-03-12 1:14 ` 2.6.25-rc5-mm1 Dave Young
2008-03-12 7:21 ` 2.6.25-rc5-mm1: NO_HZ=Y && PREEMPT_RCU=Y fails to build Laurent Riffard
2008-03-12 7:44 ` Andrew Morton
2008-03-12 21:32 ` Laurent Riffard
2008-03-12 23:43 ` Tilman Schmidt
2008-03-12 9:17 ` [BUILD_FAILURE] 2.6.25-rc5-mm1 build fails at startup_ipi_hook() with randconfig Kamalesh Babulal
2008-03-12 12:55 ` [BUG] 2.6.25-rc5-mm1 kernel panic with "Exception: 501 " on powerpc Kamalesh Babulal
2008-03-12 17:46 ` Andrew Morton
2008-03-12 17:51 ` Matthew Wilcox
2008-03-12 22:26 ` Michael Ellerman
2008-03-12 22:33 ` Matthew Wilcox
2008-03-13 13:02 ` Kamalesh Babulal
2008-03-12 20:40 ` Benjamin Herrenschmidt
2008-03-12 18:14 ` Badari Pulavarty
2008-03-12 18:10 ` 2.6.25-rc5-mm1 - x86_64 boot problem ? Badari Pulavarty
2008-03-12 18:15 ` Andrew Morton
2008-03-13 17:09 ` 2.6.25-rc5-mm1 - x86_64 boot problem with git-sched.patch Badari Pulavarty
2008-03-13 17:40 ` Badari Pulavarty
2008-03-13 17:55 ` Guillaume Chazarain
2008-03-13 18:20 ` Badari Pulavarty
2008-03-12 23:54 ` [2.6.25-rc5-mm1] BUG: spinlock bad magic early during boot Tilman Schmidt
2008-03-13 0:04 ` Andrew Morton
2008-03-13 21:48 ` Dave Hansen
2008-03-13 20:46 ` Dave Hansen
2008-03-14 0:35 ` Tilman Schmidt
2008-03-14 18:03 ` Dave Hansen
2008-03-14 20:06 ` Dave Hansen
2008-03-14 20:20 ` Linus Torvalds
2008-03-14 20:51 ` Eric Piel
2008-03-14 21:35 ` Dave Hansen
2008-03-14 22:50 ` Eric Piel
2008-03-14 23:29 ` Dave Hansen
2008-03-15 12:47 ` Tilman Schmidt
2008-03-15 19:21 ` Linus Torvalds
2008-03-15 19:42 ` Éric Piel
2008-03-15 20:19 ` Linus Torvalds
2008-03-16 0:15 ` Éric Piel
2008-03-17 17:27 ` Len Brown
[not found] ` <1205858252.21619.233.camel@queen.suse.de>
2008-03-18 20:32 ` Len Brown
2008-03-20 14:28 ` Thomas Renninger
2008-03-17 17:59 ` Len Brown
2008-03-21 13:17 ` Pavel Machek
2008-03-23 16:00 ` Dave Hansen
2008-03-24 16:03 ` Pavel Machek
2008-03-24 17:05 ` Eric Piel [this message]
2008-03-24 17:19 ` Pavel Machek
2008-03-24 17:23 ` Dave Hansen
2008-03-27 9:23 ` Helge Hafting
2008-03-17 18:05 ` Len Brown
2008-03-16 20:11 ` Dave Hansen
2008-03-17 12:23 ` Peter Zijlstra
2008-03-19 23:50 ` Tilman Schmidt
2008-03-17 17:48 ` Len Brown
2008-03-13 0:15 ` [2.6.25-rc5-mm1] WARNING: at drivers/base/sys.c:173 Tilman Schmidt
2008-03-13 18:34 ` Greg KH
2008-03-13 19:57 ` Dave Jones
2008-03-13 19:56 ` Dave Jones
2008-03-13 20:27 ` Greg KH
2008-03-14 0:01 ` Tilman Schmidt
2008-03-14 0:44 ` Dave Jones
2008-03-14 0:57 ` Zhao Yakui
2008-03-14 9:58 ` Tilman Schmidt
2008-03-15 12:16 ` Tilman Schmidt
2008-03-13 14:03 ` 2.6.25-rc5-mm1 shutdown crash Helge Hafting
2008-03-13 16:12 ` Andrew Morton
2008-03-25 12:23 ` Helge Hafting
2008-03-13 19:48 ` [2.6.25-rc5-mm1] regression: cannot run Postfix sendmail command as non-root Tilman Schmidt
2008-03-13 22:21 ` Daniel Lezcano
2008-03-14 0:08 ` Tilman Schmidt
2008-03-17 10:44 ` Daniel Lezcano
2008-03-17 12:50 ` Benjamin Thery
2008-03-17 13:35 ` Tilman Schmidt
2008-03-17 13:06 ` Tilman Schmidt
2008-03-17 13:17 ` Daniel Lezcano
2008-03-19 17:52 ` Benjamin Thery
2008-03-19 21:16 ` Andrew Morton
2008-03-19 22:14 ` Benjamin Thery
2008-03-19 22:49 ` David Miller
2008-03-20 8:26 ` Benjamin Thery
2008-03-20 10:21 ` Rafael J. Wysocki
2008-03-20 12:52 ` Pavel Emelyanov
2008-03-20 13:48 ` Benjamin Thery
2008-03-20 14:38 ` Rafael J. Wysocki
2008-03-19 23:31 ` Tilman Schmidt
2008-03-13 22:07 ` 2.6.25-rc5-mm1: "consolechars" hangs on boot Laurent Riffard
2008-03-13 22:38 ` Andrew Morton
2008-03-14 5:26 ` Oleg Nesterov
2008-03-14 21:06 ` Laurent Riffard
2008-03-15 12:03 ` Oleg Nesterov
2008-03-16 21:38 ` 2.6.25-rc5-mm1 build failure of pcsp.c Mariusz Kozlowski
2008-03-28 22:52 ` 2.6.25-rc5-mm1 sparc64 boot problems due to generic pci_enable_resources() Mariusz Kozlowski
2008-03-28 23:10 ` David Miller
2008-03-29 0:44 ` Benjamin Herrenschmidt
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=47E7DF4A.4090007@tremplin-utc.net \
--to=eric.piel@tremplin-utc.net \
--cc=akpm@linux-foundation.org \
--cc=arjanv@redhat.com \
--cc=dsdt@gaugusch.at \
--cc=ebiederm@xmission.com \
--cc=haveblue@us.ibm.com \
--cc=hch@infradead.org \
--cc=len.brown@intel.com \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=tilman@imap.cc \
--cc=torvalds@linux-foundation.org \
--cc=trenn@suse.de \
--cc=viro@ZenIV.linux.org.uk \
/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