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  1. JDK
  2. JDK-8259496

Parallel GC insists on using large pages although it failed to use them

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    Details

    • Type: Bug
    • Status: Open
    • Priority: P4
    • Resolution: Unresolved
    • Affects Version/s: 17
    • Fix Version/s: 19
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc

      Description

      This huge page setup:
      $ cat hugepages-1048576kB/free_hugepages 30
      $ cat hugepages-2048kb/free_hugepages 0

      $ java -Xmx20g -Xms20g -XX:+UseLargePages -XX:LargePageSizeInBytes=1g -XX:+PrintFlagsFinal -XX:+AlwaysPreTouch -XX:+UseParallelGC Hello

      OpenJDK 64-Bit Server VM warning: Failed to reserve shared memory. (error = 1)
      [1.667s][warning][gc] Pretouch size 4294967296 chunk size 1073741824 page size 1073741824
      [1.668s][warning][gc] Pretouch size 1073741824 chunk size 1073741824 page size 1073741824
      [1.668s][warning][gc] Pretouch size 1073741824 chunk size 1073741824 page size 1073741824
      [5.526s][warning][gc] Pretouch size 15032385536 chunk size 1073741824 page size 1073741824

      Parallel gc fails on allocating 1g pages here, but still pre-touches with 1g page size.

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              Assignee:
              Unassigned Unassigned
              Reporter:
              tschatzl Thomas Schatzl
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                Created:
                Updated: