Re: [crash] kernel BUG at drivers/cpufreq/cpufreq.c:1060!

Dave Jones
2007-12-12T16:41:07Z

On Wed, Dec 12, 2007 at 10:11:44AM +0100, Ingo Molnar wrote:

> 2.6.24-rc4-git5, got this cpufreq crash on x86 64-bit, during 'make
> randconfig' random bootup testing:

You hit all the fun bugs.

Just before we initialise cpufreqs notifier list..

> Testing NMI watchdog ... <4>WARNING: CPU#0: NMI appears to be stuck (0->0)!

eek?

> powernow-k8: Found 1 AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ processors (1 cpu cores) (version 2.20.00)
> powernow-k8: BIOS error - no PSB or ACPI _PSS objects
> ------------[ cut here ]------------
> kernel BUG at drivers/cpufreq/cpufreq.c:1060!

The actual BUG you hit is

if (unlikely(lock_policy_rwsem_write(cpu)))
BUG();

It _looks_ like we're leaking a refcount on that lock, but
I don't see where. It's a shame you can't reproduce this easily,
as cpufreq.debug=7 would give us more clues.
(And CONFIG_CPUFREQ_DEBUG=y)

I'll think about this some more.

Dave

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