Re: [PATCH V4 1/2] perf & kvm: Enhance perf to collect KVM guest os statistics from host side

[Avi Kivity <avi@redhat.com>]

On 04/17/2010 10:13 PM, Ingo Molnar wrote:
> * Avi Kivity<avi@redhat.com>  wrote:
>
>    
>> On 04/16/2010 10:34 AM, Zhang, Yanmin wrote:
>>      
>>> Below is the kernel patch to enable perf to collect guest os statistics.
>>>
>>> Joerg,
>>>
>>> Would you like to add support on svm? I don't know the exact point to trigger
>>> NMI to host with svm.
>>>
>>> See below code with vmx:
>>>
>>> +		kvm_before_handle_nmi(&vmx->vcpu);
>>>   		asm("int $2");
>>> +		kvm_after_handle_nmi(&vmx->vcpu);
>>>
>>> Signed-off-by: Zhang Yanmin<yanmin_zhang@linux.intel.com>
>>>        
>> Can you please split it further?
>>
>> Patch 1 introduces perf_register_guest_info_callbacks() and related. Ingo
>> can merge this into a branch in tip.git. Patch 2 is just the kvm bits, I'll
>> apply that after merging the branch with patch 1. Patch 3 adds the
>> tools/perf changes.
>>
>> This way perf development can continue on tip.git, and kvm development can
>> continue on kvm.git, without the code bases diverging and requiring a merge
>> later.
>>      
> I'd like to pull the KVM bits from you into perf - so that there's a testable
> form of the changes. We can do that via a branch that has 1-2 changes, plus
> minimal conflicts down the line, right?
>    

We can try doing this (currently we don't, but this is simple enough 
that we could).  I'd still like 1-2 in two patches.

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