From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Arnd Hannemann <hannemann@nets.rwth-aachen.de>,
Ingo Molnar <mingo@elte.hu>,
Arnd Hannemann <Arnd.Hannemann@nets.rwth-aachen.de>,
LKML <linux-kernel@vger.kernel.org>,
"hannes@cmpxchg.org" <hannes@cmpxchg.org>,
"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [bisected] 2.6.31 regression: fails to boot as xen guest
Date: Tue, 25 Aug 2009 12:31:52 -0700 [thread overview]
Message-ID: <4A943C28.2040104@goop.org> (raw)
In-Reply-To: <1251225834.13451.13.camel@penberg-laptop>
On 08/25/09 11:43, Pekka Enberg wrote:
> Aha, the previous patch worked because I #ifdef the WP test completely.
> Jeremy, the root cause here is that we do the WP test much earlier than
> before. Even with the test moved to trap_init(), we do it early compared
> to what we did before.
>
> I guess Xen is not prepared to handle traps this early in the boot
> sequence? Can we fix that?
>
The crash is in the event (interrupt) path, which shouldn't be involved
in trap handling at all. I'm wondering if interrupts are getting
enabled as a side-effect of handling the trap.
J
WARNING: multiple messages have this Message-ID (diff)
From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Arnd Hannemann <hannemann@nets.rwth-aachen.de>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
LKML <linux-kernel@vger.kernel.org>,
"hannes@cmpxchg.org" <hannes@cmpxchg.org>,
Ingo Molnar <mingo@elte.hu>,
"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
Arnd Hannemann <Arnd.Hannemann@nets.rwth-aachen.de>
Subject: Re: [bisected] 2.6.31 regression: fails to boot as xen guest
Date: Tue, 25 Aug 2009 12:31:52 -0700 [thread overview]
Message-ID: <4A943C28.2040104@goop.org> (raw)
In-Reply-To: <1251225834.13451.13.camel@penberg-laptop>
On 08/25/09 11:43, Pekka Enberg wrote:
> Aha, the previous patch worked because I #ifdef the WP test completely.
> Jeremy, the root cause here is that we do the WP test much earlier than
> before. Even with the test moved to trap_init(), we do it early compared
> to what we did before.
>
> I guess Xen is not prepared to handle traps this early in the boot
> sequence? Can we fix that?
>
The crash is in the event (interrupt) path, which shouldn't be involved
in trap handling at all. I'm wondering if interrupts are getting
enabled as a side-effect of handling the trap.
J
next prev parent reply other threads:[~2009-08-25 19:31 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-25 15:48 [bisected] 2.6.31 regression: fails to boot as xen guest Arnd Hannemann
2009-08-25 16:29 ` Pekka Enberg
2009-08-25 16:29 ` Pekka Enberg
2009-08-25 16:49 ` Arnd Hannemann
2009-08-25 16:49 ` Arnd Hannemann
2009-08-25 16:52 ` Pekka Enberg
2009-08-25 16:52 ` Pekka Enberg
2009-08-25 17:49 ` Arnd Hannemann
2009-08-25 17:49 ` Arnd Hannemann
2009-08-25 18:03 ` Pekka Enberg
2009-08-25 18:03 ` Pekka Enberg
2009-08-25 18:08 ` Jeremy Fitzhardinge
2009-08-25 18:08 ` Jeremy Fitzhardinge
2009-08-25 18:22 ` Arnd Hannemann
2009-08-25 18:22 ` Arnd Hannemann
2009-08-25 18:25 ` Ingo Molnar
2009-08-25 18:25 ` Ingo Molnar
2009-08-25 18:30 ` Jeremy Fitzhardinge
2009-08-25 18:38 ` Arnd Hannemann
2009-08-25 18:38 ` Arnd Hannemann
2009-08-25 18:43 ` Pekka Enberg
2009-08-25 18:43 ` Pekka Enberg
2009-08-25 19:31 ` Jeremy Fitzhardinge [this message]
2009-08-25 19:31 ` Jeremy Fitzhardinge
2009-08-25 19:30 ` Jeremy Fitzhardinge
2009-08-25 19:30 ` Jeremy Fitzhardinge
2009-08-25 18:58 ` Pekka Enberg
2009-08-25 19:07 ` Pekka Enberg
2009-08-25 19:07 ` Pekka Enberg
2009-08-25 19:13 ` Arnd Hannemann
2009-08-25 19:13 ` Arnd Hannemann
2009-08-26 9:59 ` Benjamin Herrenschmidt
2009-08-25 18:06 ` Jeremy Fitzhardinge
2009-08-25 18:06 ` Jeremy Fitzhardinge
2009-08-25 18:14 ` Pekka Enberg
2009-08-25 18:14 ` Pekka Enberg
2009-08-26 11:54 ` Pasi Kärkkäinen
2009-08-26 12:00 ` Pekka Enberg
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