Re: pinning CPUs in bhyve

2014-04-11 Thread Peter Grehan

Hi Steve,


Can someone help me understand the cpu pinning feature in bhyve? I'm afraid the
docs have confused me:

  -p pinnedcpu
   Force guest virtual CPUs to be pinned to host CPUs.  Virtual CPU n is pinned
   to host CPU pinnedcpu+n.

What would the arg looks like? Something like -p 0,1,2,3 ?


 No - currently the parameter can only select the starting host CPU 
e.g. "-p 3" for a quad vCPU guest will force the vCPU threads to be 
pinned to host CPUs 3,4,5 and 6.



Also, is there like to be much or any benefit from it?


 Not really. It's for very specialized use cases, and could actually 
hurt performance. Not too different in that respect than cpuset with 
user processes.


later,

Peter.

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pinning CPUs in bhyve

2014-04-11 Thread Steve Wills
Hi,

Can someone help me understand the cpu pinning feature in bhyve? I'm afraid the
docs have confused me:

 -p pinnedcpu
  Force guest virtual CPUs to be pinned to host CPUs.  Virtual CPU n is pinned
  to host CPU pinnedcpu+n.

What would the arg looks like? Something like -p 0,1,2,3 ?

Also, is there like to be much or any benefit from it?

Thanks,
Steve
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