Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8255737

Zero: DO_UPDATE_INSTRUCTION_COUNT should only update when relevant VM flags are set

    XMLWordPrintable

    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 8, 11, 15, 16
    • Fix Version/s: 16
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
    • Resolved In Build:
      b23

      Description

      Everywhere else in VM code we effectively do:

        if (CountBytecodes || TraceBytecodes || StopInterpreterAt) BytecodeCounter::...
        if (PrintBytecodeHistogram) BytecodeHistogram::...

      But not in DO_UPDATE_INSTRUCTION_COUNT macro.

      Adding these flags avoid the writes to statistics what would never be used (and those writes can even contend, afaics).

      This change drops the Linux x86_64 Zero fastdebug build time from ~18m to ~17.5m.

        Attachments

          Issue Links

          links to

          Commit Commit openjdk/jdk/f389a718

          Review Review openjdk/jdk/997

            Activity

              People

              Assignee:
              shade Aleksey Shipilev
              Reporter:
              shade Aleksey Shipilev
              Votes:
              0 Vote for this issue
              Watchers:
              3 Start watching this issue

                Dates

                Created:
                Updated:
                Resolved: