On Mon, 2 Dec 2024 17:41:30 GMT, Coleen Phillimore <cole...@openjdk.org> wrote:
> Putting generated LambdaForm$MH and $DMH in non-class space seems to cause > excess dependency checking for c2 compiled code and shows a performance > regression in a new JMH performance test for MethodHandles (to be checked in > at a later time). > > When I made this abstract rather than final, I thought there were a many > generated classes but I haven't found in testing more than a small > percentage. For example, Dacapo xalan there are 43/1000 classes that are > these generated classes. In Eric's new JMH test, it was more like 51/681. > Special casing "AllStatic" classes to go in non-class metaspace is a bit too > risky at this time. If it does become a problem with limited class > metaspace, we can create another attribute to use. > > Tested with tier1-4 and the JMH test. Thanks Eric Caspole for finding this > and all the testing. Thank you for the code review. ACC_FINAL is a good thing to have for these generated classes as it helps the JIT compilers. It would be really nice if there was some ACC_ALLSTATIC which meant that the code cannot create instances of these classes but that doesn't exist. ------------- PR Comment: https://git.openjdk.org/jdk/pull/22493#issuecomment-2514584072
