Gen ZGC OOM after 12 hours

[Cody Lerum]

Recently after updating from 21.0.2 to 21.0.3 I decided to switch from
standard ZGC to generational ZGC for a wildfly application server
which runs with the following settings normally.

-Xmx8G -XX:SoftMaxHeapSize=6G -XX:+UseZGC -XX:ReservedCodeCacheSize=512m

After about 12 hours, and really about 2 hours after usage for the day
started to ramp up the instance crashed with an status 137 and based
on all the info it just exhausted its memory. it seemed a bit similar
to JDK-8282357.

Unfortunately I didn't get a hs_err file, but I do have the jfr files
for the 20 minutes or so leading up to it. I've shut off gen zgc and
I'm just using normal zgc for now for the last week without issues,
but I wanted to let you know I have those JFR files if you think they
may be of use.

Thanks!

Cody Lerum