Class unloading in jdk15

[Vicente Rossello]

Hi,

I tried shenandoah with JDK15 (latest build from builds.shipilev.net) in
our build, it works better than with G1, without even tuning anything, so
that's great.

I also tried enabling class unloading (we have it disabled with G1,
we don't really get a lot of memory back, but GC times do increase a little
bit), but it didn't work with shenandoah, GC times become very high.

These are GC logs of our full build, with and without class unloading:
https://gist.github.com/cocorossello/2c7e774b89f7cb3e3c97ec5758d879ff

Our application is a web application, using dependency injection and
dynamic proxies. I have tried to make a reproducer but I couldn't, it's not
an easy task... Maybe the problem comes from dependency injection that
creates proxies...

I have tried reducing the build and enabling class load/unload logs
(-verbose:class), to see if that helps:

https://gist.github.com/cocorossello/f77049148e694b91e785696b1808fb4e  ->
Reduced build, class unloading off, verbose class define


https://gist.github.com/cocorossello/52c1c88c782adc1a0537fd8aa92a6c82  ->
Reduced build, class unloading on, verbose class define

Please let me know if I can do something else, unfortunately I can't share
the code.

Thank you,
Vicente.