Re: kernel bug in kvm_intel

[Avi Kivity <avi@redhat.com>]

On 10/30/2009 08:07 PM, Andrew Theurer wrote:
>
> I have finally bisected and isolated this to the following commit:
>
> ada3fa15057205b7d3f727bba5cd26b5912e350f
> http://git.kernel.org/?p=virt/kvm/kvm.git;a=commit;h=ada3fa15057205b7d3f727bba5cd26b5912e350f
>    
>> Merge branch 'for-linus' of git://git./linux/kernel/git/tj/percpu
>>
>> * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
>>    powerpc64: convert to dynamic percpu allocator
>>    sparc64: use embedding percpu first chunk allocator
>>    percpu: kill lpage first chunk allocator
>>    x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
>>    percpu: update embedding first chunk allocator to handle sparse units
>>    percpu: use group information to allocate vmap areas sparsely
>>    vmalloc: implement pcpu_get_vm_areas()
>>    vmalloc: separate out insert_vmalloc_vm()
>>    percpu: add chunk->base_addr
>>    percpu: add pcpu_unit_offsets[]
>>    percpu: introduce pcpu_alloc_info and pcpu_group_info
>>    percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
>>    percpu: add @align to pcpu_fc_alloc_fn_t
>>    percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
>>    percpu: drop @static_size from first chunk allocators
>>    percpu: generalize first chunk allocator selection
>>    percpu: build first chunk allocators selectively
>>    percpu: rename 4k first chunk allocator to page
>>    percpu: improve boot messages
>>    percpu: fix pcpu_reclaim() locking
>>      
> The previous commit (5579fd7e6aed8860ea0c8e3f11897493153b10ad) does not
> this problem.  FYI, this problem only occurs when oprofile is active.
>
> Any idea what in this commit might be the issue?
>
>    

5579 is not the preceding commit, it is the merged branch:

commit ada3fa15057205b7d3f727bba5cd26b5912e350f
Merge: 2f82af0 5579fd7
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Tue Sep 15 09:39:44 2009 -0700

     Merge branch 'for-linus' of 
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu


What happens with 2f82af0?

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.