It's all about the tiered compilation. Tons of unused but eagerly compiled code w/ C1 (the dumb and fast compiler) that never reached the proper C2.

The issue has been three since 6.0.23 when the -XX:+TieredCompilation defaulted to true. (hmm, or was it 6.0.25?)

I'd say nothing really new. If you run a server, just disable tired compilation altogether. It might cost few seconds slower startup but that's it.