linux-kernel - Re: 2.6.{26.2,27-rc} oops on virtualbox

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Message-ID: <20080827161346.35b48d75@doriath.conectiva>
Date:	Wed, 27 Aug 2008 16:13:46 -0300
From:	"Luiz Fernando N. Capitulino" <lcapitulino@...driva.com.br>
To:	Gerhard Brauer <gerhard.brauer@....de>
Cc:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...e.hu>,
	linux-kernel@...r.kernel.org
Subject: Re: 2.6.{26.2,27-rc} oops on virtualbox

Em Tue, 26 Aug 2008 22:34:49 +0200
Gerhard Brauer <gerhard.brauer@....de> escreveu:

| On Tue, Aug 26, 2008 at 02:15:58PM -0400, Mathieu Desnoyers wrote:
| > 
| > Ok, it might still be caused by paravirt and alternatives instruction
| > patching. What if you also do :
| > 
| > alternative_instructions()
| > 
| > +        unsigned long flags;
| >         /* The patching is not fully atomic, so try to avoid local interruptions
| >            that might execute the to be patched code.
| >            Other CPUs are not running. */
| >         stop_nmi();
| > #ifdef CONFIG_X86_MCE
| >         stop_mce();
| > #endif
| > +        local_irq_save(flags);
| > 
| > 
| > ...
| > +        local_irq_restore(flags);
| >         restart_nmi();
| > #ifdef CONFIG_X86_MCE
| >         restart_mce();
| > #endif
| > 
| > ?
| 
| Hej! This last changes (in addition to the others you mentioned) seems
| to be a good shot. I could reboot 8 times the guest, compile several
| packages (something which always leeds to the oops) and currently i
| build two big packages simultan. So this is heavy IO.

 Yeah, it works for me too and it's good to know that you are doing
additional tests. I'm doing only boot tests... I was testing lots of
kernels and doing additional tests would take a lot of time.

 Now, what does this mean? Is VirtualBox issuing interrupts when it
shouldn't or should this section of the code be better protected?

-- 
Luiz Fernando N. Capitulino
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