Re: [PATCH 2/3] KVM: improve trace events of vmexit/mmio/ioport

[Xiao Guangrong]

On 01/16/2012 05:38 PM, Avi Kivity wrote:

> On 01/16/2012 11:32 AM, Xiao Guangrong wrote:
>> - trace vcpu_id for these events
> 
> We can infer the vcpu id from the kvm_entry tracepoints, no?
> 


Thanks for your review, Avi!

Hmm. i think it is hard to do since the vcpu thread can be scheduled
anytime, one example is as follow:

CPU 0

kvm_entry vcpu 0
......
kvm_entry vcpu 1
......
event1 occurs
......
event2 occurs

It is hard to know the event belong to which kvm_entry?

>> - add kvm_mmio_done to trace the time when mmio/ioport emulation is completed
> 
> ditto?
> 


I think is ok to get the event end time by using kvm_entry.

> 
> Relying on the existing tracepoints will make the tool work on older
> kernels.
> 


We can drop all new events, but unfortunately, the information of the origin
tracepoints is not enough, at least vcpu_id need be traced in theses events
to match its events. Yes?

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/