Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-6403290

CMS: abortable preclean phase performance

XMLWordPrintable

    • gc
    • 5.0
    • 5.0
    • generic
    • generic

      The so-called "abortable preclean phase" was implemented as a way to
      "continue lazy precleaning" of the CMS generation while waiting to
      schedule the remark roughly midway between scavenges in order to reduce
      the mutator impact of potential back-to-back stop-world pauses that
      might otherwise occur.

      Recent evidence however suggests that abortable precleaning is not
      meeting these goals much of the time. To wit, in some cases abortable
      preclean makes matters worse by extending the length of the CMS cycle
      by a large amount. This has several deleterious effects, besides the
      obvious one of increase floating garbage and footprint on account of
      the longer occasional cycle: the large resulting volatility in CMS
      cycle lengths can defeat ergonomics by requiring artificially large
      padding factors, or of causing inefficient operation on account of
      the volatility in the sensor data.

      The heuristic needs to be revisited to reduce these bad effects.

            Unassigned Unassigned
            ysr Y. Ramakrishna
            Votes:
            0 Vote for this issue
            Watchers:
            2 Start watching this issue

              Created:
              Updated:
              Resolved:
              Imported:
              Indexed: