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  1. JDK
  2. JDK-7003380

active_processor_count() unaware of cpusets

    Details

    • Type: Enhancement
    • Status: Closed
    • Priority: P5
    • Resolution: Duplicate
    • Affects Version/s: 7
    • Fix Version/s: None
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
    • CPU:
      x86
    • OS:
      linux

      Description

      A DESCRIPTION OF THE REQUEST :
      The VM does not use cpuset information on linux to determine the number of available processors. This can result in a very inflated number of processors reported. The active processor count is used a number of times in the VM internals. It is also reported by Runtime.availableProcessors() which is used, among other places, by the fork/join framework. I have worked on a patch that uses the cpuset information when available, and otherwise reverts back to the original method of detecting the number of processors.

      JUSTIFICATION :
      With the patch, Runtime.availableProcessors() reports 3968 on a SGI UV 1000 when the cpuset policy has restricted the process to 32 cores. With the patch, it reports 32.

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              • Assignee:
                Unassigned
                Reporter:
                ndcosta Nelson Dcosta (Inactive)
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