Re: Poor HVM performance with 8 vcpus

[Juergen Gross <juergen.gross@ts.fujitsu.com>]

Ian Pratt wrote:
>  
>> Are there any other of these heuristics tucked away in xen? Would there
>> be any benefit to specifying the OS being virtualised in the config? Eg
>> "os=windows"?
> 
> That's really the only one that springs to mind.
> 
> Given how simple a predictor would be, I think that's the best approach.
> 
> Setting the OS in the config file is a little tricky as in a couple of instances you'd want to know the exact version (linux moved the 64b direct mapped region at some point during 2.6 development).

I think it is a bad idea in most cases to use such a basic parameter like
"os=xyz" to tune some specific behaviour. It may be useful to set some default
parameters, but there should be an explicit parameter as well, e.g.
"shadow_heuristic=direct-mapped@address"


Juergen

-- 
Juergen Gross                 Principal Developer Operating Systems
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