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

[Avi Kivity <avi@qumranet.com>]

Chris Lalancette wrote:
> Avi Kivity wrote:
>   
>> 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.
>>
>>     
>
> Ah.  Just adding a "me too"; I didn't get a chance to debug it yesterday, but I
> was seeing similar problems.  If I disabled in-kernel pit with -no-kvm-pit, all
> was well.
>   

How to fix it, though?  the only idea that comes to mind is to affine 
the hrtimer with vcpu0 (like the local apic timers) which would mean we 
only need to unwait the waitqueue, and never need to send the IPI.  
Would slightly improve performance as well.

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


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