Re: KVM Test result, kernel 873c05f.., userspace d102d75..

[Avi Kivity <avi@qumranet.com>]

Avi Kivity wrote:
> Yang, Sheng wrote:
>> On Thursday 24 April 2008 19:37:03 Avi Kivity wrote:
>>  
>>> Yunfeng Zhao wrote:
>>>    
>>>> Hi All,
>>>>
>>>> This is today's KVM test result against kvm.git
>>>> 873c05fa7e6fea27090b1bf0f67a073eadb04782 and kvm-userspace.git
>>>> d102d750f397b543fe620a3c77a7e5e42c483865.
>>>>       
>>> I suspect 873c05fa7e6fea27090b1bf0f67a073eadb04782 itself, it's the 
>>> only
>>> thing that has any chance of badness.
>>>
>>> Marcelo, any idea?  Perhaps due to load, interrupts accumulate and 
>>> can't
>>> be injected fast enough?
>>>
>>> These tests are run on a 2.6.22 host, which has a hacked
>>> smp_call_function_single() in external-module-compat.h, which may
>>> exaberate the problem.
>>>     
>>
>> Yeah, I suspect the commit too(I tried tip without that, and found 
>> mostly alright). In fact, I didn't use kvm_vcpu_kick() just because 
>> that I found this function may causing hang on my host... But I 
>> didn't do more investigate so I can't tell what's wrong, then I just 
>> chose way to keep it working... I am sorry for not clarify...
>>   
>
> I think smp_call_function_single() is miscompiled when using the 
> compatibility code.  I took it out-of-line to be sure (it is now in 
> kernel/external-module-compat.c).
>
> No evidence, but...
>

Ok.  __pit_timer_fn() is called from an interrupt, which then calls 
smp_call_function_single(), which calls spin_lock().  If we've already 
taken the lock, we hang.

-- 
error compiling committee.c: too many arguments to function


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