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  1. JDK
  2. JDK-8137022

Concurrent refinement thread adjustment and (de-)activation suboptimal

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    • gc
    • b21

    Description

      After every GC G1 readjusts concurrent refinement thresholds with the goal to have X amount of unprocessed buffers at the start of GC to process in the update RS phase. X is calculated from the time available for the Update RS phase.

      The current calculation has the following issues:
      - it allows the green threshold to get zero. This means that both refinement threads *and* mutators are competing for the buffers. There is no need to run the threads.
      - there are magic factors to create the yellow and red thresholds that have nothing to do with actual application.
      - (this may be another issue) activating more refinement threads is not in any way related to the rate they are added to the queue. Ideally more threads would be dynamically activated as the rate the buffers are added to the queue changes

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          csr for

          CSR - null JDK-8294206 Concurrent refinement thread adjustment and (de-)activation suboptimal

          • P3 - Major loss of function.
          • Closed
          duplicates

          Enhancement - null JDK-8172918 Investigate ways to push Update RS work into the concurrent phase

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Closed
          is blocked by

          Enhancement - null JDK-8155996 Improve concurrent refinement green zone control

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Enhancement - null JDK-8156696 Simplify PtrQueueSet initialization

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved
          relates to

          Enhancement - null JDK-8293616 Concurrent refinement by mutators only processes one buffer

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Open

          Enhancement - null JDK-8069330 Adjustment of concurrent refinement thresholds does not take hot card cache into account

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Enhancement - null JDK-8231153 Improve concurrent refinement statistics

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. JDK-8133051 Concurrent refinement threads may be activated and deactivated at random

          • P2 - Crashes, loss of data, severe memory leak.
          • Closed

          Enhancement - null JDK-8139652 Mutator refinement processing should take the oldest dirty card buffer

          • P3 - Major loss of function.
          • Resolved
          links to

          Commit Commit openjdk/jdk/028e8b3d

          Review Review openjdk/jdk/10256

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              kbarrett Kim Barrett
              tschatzl Thomas Schatzl
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              Dates

                Created:
                Updated:
                Resolved: