Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8332516

Serial: Always sample promoted bytes to avoid getting stuck in Full GCs

    XMLWordPrintable

Details

    • Enhancement
    • Resolution: Fixed
    • P4
    • 24
    • 23
    • hotspot
    • gc
    • b02

    Description

      `TenuredGeneration::update_gc_stats` records #promoted bytes after gc. The promoted-bytes metric is updated only after young-gc though.

      This can lead to outdated promoted-bytes after a full-gcs. `TenuredGeneration::promotion_attempt_is_safe` use this metric to decide whether to start young-gc or full-gc, so this outdated promoted-bytes can result into choosing full-gc all the time if old-gen free-space is tight.

      Therefore, the promoted-byte metric should be updated both after young-gc and after full-gc so that after some full-gc that reduces used-heap, one can get back to running young-gc.

      Attachments

        Issue Links

          Activity

            People

              ayang Albert Yang
              ayang Albert Yang
              Votes:
              0 Vote for this issue
              Watchers:
              3 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: