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.