On Wed, Jul 02, 2008 at 12:37:54PM +0200, Gabor Gombas wrote:

On Tue, Jul 01, 2008 at 09:45:08PM +0200, Michael Bussmann wrote:

quoted

So far I tried
	- Replaced IDE cables
	- kernel upgrades up to 2.6.25.9
	- removed one drive from the RAID, thus running in degraded mode
	- disabled CPU frequency scaling
	- put one drive on the PDC20276, the other on the ICH4 (82801DB)

Set up netconsole or serial console, boot with nmi_watchdog=2, and wait
for a lockup.

Some motivation: I have a feeling that the HPET problem in 2.6.25 is
actually biting people other than me. But if you do not enable the NMI
watchdog and do not have a way to save the resulting Oops, then you
will never know what hit you. SysRq+W will show tasks blocked in places
related to disk I/O, but that's not the real reason, so messing with
the disks will not help you in this case.

And this also explains why machines w/o HPET (or HPET being disabled by
the BIOS or otherwise unaffected for yet unknown reasons) can run
2.6.25.x just fine.

Gabor

-- 
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     MTA SZTAKI Computer and Automation Research Institute
                Hungarian Academy of Sciences
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