Cause of JVM exiting with Realtime signal 28

[Tony]

I hope this isn't a FAQ question. Does anyone know what would cause
the HotSpot JVM running on RedHat Linux 8 to exit with "Realtime
signal 28"? We believe that the actual signal code is 61. This
problem is pretty intermittant and we can't find any documentation on
the JVM use of realtime signals. Anyone ever seen this? Any insights
welcome.

Thanks,
Tony