G1GC not cleaning old gen

[bilal qureshi]

Hi,

I'm using solr cloud 9.1.1 on solr cloud cluster start initial heap it
takes around 400 MB out of 12 GB. After some queries on solr heap increases
to 8 GB. And when I reload the collection it reduces to 7GB.
using G1GC in this case.

Running the same testcase with ZGC, it reduces heap to less than 1 GB.

Thanks
Bilal.