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Subject: Re: PROBLEM: oops
From: Peter Zijlstra <peterz@infradead.org>
To: Pawel Golaszewski <blues@gda.pl>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>
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Date: Tue, 25 Aug 2009 16:44:43 +0200
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On Tue, 2009-08-25 at 16:28 +0200, Pawel Golaszewski wrote:
> On Tue, 25 Aug 2009, Peter Zijlstra wrote:
> > > > > No matter which kernel I'm using (2.6.27 - 2.6.30) it crashes. 
> > > > > Works for few minutes and crashes. Even SysRq doesn't work. Dunno 
> > > > > how to trigger it on other machine than mine (I have two, both 
> > > > > affected). If more info is required - just ask.
> > > > > [...]
> > > > > [24483.211036] BUG: unable to handle kernel NULL pointer dereference at 00000058
> > > > > [24483.211144] IP: [<c081cf9a>] pick_next_task_fair+0x6a/0x100
> > > > > [24483.211247] Oops: 0000 [#1] SMP 
> > > > > [24483.211300] Modules linked in: netconsole configfs dm_mod softdog sch_sfq xfs raid10 uhci_hcd eepro100 ppdev parport_pc floppy parport ehci_hcd e100 piix i2c_piix4 thermal psmouse e1000 container ide_core usbcore mii button pcspkr serio_raw processor i2c_core sg evdev ext3 jbd mbcache scsi_wait_scan sd_mod crc_t10dif ata_piix libata dock aic7xxx sym53c8xx scsi_transport_spi scsi_mod raid1 md_mod
> > > > > [24483.211878] 
> > > > > [24483.211910] Pid: 1677, comm: md2_raid10 Not tainted (2.6.27.31-1 #1)
> > > > 
> > > > So you're saying .30 crashes at the exact same place?
> > > 
> > > Well... I'm not able to catch anything on .30 No sign on netconsole, 
> > > black screen on monitor...
> > 
> > Could you share your .config?
> 
> Sure, I forgot:
> http://www.blues.gda.pl/2.6.27.31.config.bz2

Right, are you actually using group scheduling? could you try to
reproduce without that?

CONFIG_GROUP_SCHED=n