RFR: 8284686: Interval of < 1 ms disables ExecutionSample events [v7]

[Johannes Bechberger]

> Fixes the issue by rounding the period interval to the next full millisecond larger than zero.
> 
> The following from the bug report works now:
> 
> java -XX:StartFlightRecording=filename=flight.jfr,jdk.ExecutionSample#period=999us CLASS_FILE; jfr print --events jdk.ExecutionSample flight.jfr
> 
> It considers the period to be `1ms`, producing the recording as expected.

Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:

  Update documentation

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8183/files
  - new: https://git.openjdk.java.net/jdk/pull/8183/files/e5b7f55c..eda59421

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8183&range=06
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8183&range=05-06

  Stats: 5 lines in 2 files changed: 2 ins; 2 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8183.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8183/head:pull/8183

PR: https://git.openjdk.java.net/jdk/pull/8183