[ET Trac] [Einstein Toolkit] #1850: Severe performance problem on Stampede

[Einstein Toolkit]

#1850: Severe performance problem on Stampede
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  Reporter:  hinder      |       Owner:                     
      Type:  defect      |      Status:  confirmed          
  Priority:  major       |   Milestone:                     
 Component:  SimFactory  |     Version:  development version
Resolution:              |    Keywords:                     
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Comment (by knarf):

 To summarize the current status: setting KMP_AFFINITY seems to be
 necessary for performance when using SystemTopology, but is harmful when
 not using it: either you have to use both, or none. Do I understand this
 correctly?

 If so:
 - Is it understood why using SystemTopology results in poor performance
 when KMP_AFFINITY isn't set?
 - Is it understood why using KMP_AFFINITY results in poor performance when
 not using SystemTopology (but not using KMP_AFFINITY seems to be fine)?

 My comments: It could be that 'using KMP_AFFINITY" isn't the right way to
 think about this. We set it specifically to "norespect,compact". Maybe we
 should set it to something different to work without SystemTopology.

-- 
Ticket URL: <https://trac.einsteintoolkit.org/ticket/1850#comment:8>
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