Re: [PATCH] add PLE stats to kvmstat

[Xiao Guangrong <xiaoguangrong.eric@gmail.com>]

On 07/06/2012 09:22 PM, Andrew Theurer wrote:
> On Fri, 2012-07-06 at 15:42 +0800, Xiao Guangrong wrote:
>> On 07/06/2012 05:50 AM, Andrew Theurer wrote:
>>> I, and I expect others, have a keen interest in knowing how often we
>>> exit for PLE, and also how often that includes a yielding to another
>>> vcpu.  The following adds two more counters to kvmstat to track the
>>> exits and the vcpu yields.  This in no way changes PLE behavior, just
>>> helps us track what's going on.
>>>
>>
>> Tracepoint is a better choice than the counters you used. :)
> 
> Xiao, is kvmstat considered to be deprecated?  Or are debug stats like
> this just generally favored to be processed via something like perf
> instead of debugfs?

Andrew, please refer to Documentation/feature-removal-schedule.txt,
it says:

What:   KVM debugfs statistics
When:   2013
Why:    KVM tracepoints provide mostly equivalent information in a much more
        flexible fashion.

You can use tracepoints instead of your debugfs-counters in this patch.

>  Should we be removing kvmstat?
> 

Some months ago, i implemented 'perf kvm-events' which can analyse kvm
events more smartly, the patchset can be found at:
	https://lkml.org/lkml/2012/3/6/86

Avi said it may instead of kvmstat, but i am too busy to update this
patchset. :)