RFR: JDK-8324287: Record total and free swap space in JFR

Fri Jan 26 07:58:48 UTC 2024

Total and free swap space should be recorded in JFR, because it is important to know e.g. in case of memory shortages.

Currently we only have a container related event (ContainerMemoryUsage) that provides some info but no general event.
PhysicalMemory could be enhanced or a new event added.

There is already some coding (see Java_com_sun_management_internal_OperatingSystemImpl_getTotalSwapSpaceSize0 and
Java_com_sun_management_internal_OperatingSystemImpl_getFreeSwapSpaceSize0) for the swap space info retrieval.

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Commit messages:
 - JDK-8324287

Changes: https://git.openjdk.org/jdk/pull/17581/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17581&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8324287
  Stats: 161 lines in 11 files changed: 160 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17581.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17581/head:pull/17581

PR: https://git.openjdk.org/jdk/pull/17581