Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8027295

Free CSet takes ~50% of young pause time

    XMLWordPrintable

Details

    • gc
    • b08

    Backports

      Description

        In the refworkload/wls_webapp_atomic JSP-HTTPS-POST-3 benchmark freeing the collection set takes ~50% of total pause time with G1.

        Command line to run:

        -showversion -Xmx8g -Xms8g -XX:+UseLargePages -XX:+UseG1GC -XX:+UnlockExperimentalVMOptions -XX:G1MaxNewSizePercent=29 -XX:+UseAdaptiveSizePolicy -XX:+AlwaysPreTouch

        See the attached figure wls_webapp_atomic-long-free-cset.png which shows a stacked graph of the pause time time consumers. The gray area represents the Free CSet time.

        The problematic CSet component is most likely cleaning up the sparse table (but needs to be verified).

        Attachments

          Issue Links

            backported by

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8038249 Free CSet takes ~50% of young pause time

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

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8045278 Free CSet takes ~50% of young pause time

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

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8053394 Free CSet takes ~50% of young pause time

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

            Enhancement - null JDK-8034842 Parallelize the Free CSet phase in G1

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

            Enhancement - null JDK-8034868 Extract G1 From Card Cache into separate class

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

            Enhancement - null JDK-8035815 Cache-align and pad the from card cache

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

            Enhancement - null JDK-6868854 G1: Eliminate serial Other times at the end of a GC pause

            • P3 - Major loss of function.
            • Closed

            Enhancement - null JDK-8034873 Concurrent collection set freeing

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

            Activity

              People

                tschatzl Thomas Schatzl
                tschatzl Thomas Schatzl
                Votes:
                0 Vote for this issue
                Watchers:
                4 Start watching this issue

                Dates

                  Created:
                  Updated:
                  Resolved: