RFR (S): 8165859: gcTaskThread is missing volatile qualifier and barriers for _time_stamps

[Kim Barrett]

> On Sep 20, 2016, at 3:47 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
> Unfortunately, I'm coming to believe there's some questionable code
> here, and throwing a volatile and maybe a barrier or two at it doesn't
> look like an improvement to me.

Stefan Karlsson pointed to another bug in this area:
https://bugs.openjdk.java.net/browse/JDK-8024399
PrintGCTaskTimeStamps: amount of tasks reported for GC-thread sometimes differs from expected value

After reading through that and related stuff, I'm inclined toward
closing this bug (JDK-8165859) as a duplicate of JDK-8024399.