On Thu, 29 Aug 2024 17:45:17 GMT, Markus Grönlund <mgron...@openjdk.org> wrote:
>> I now read the JIRA issue. JFR do process loads of >> java/lang/invoke/LambdaForm$MH and derivatives. > > It's fine to have each Klass* report whether it can be compressed. If not, it > will be represented using the non-compressed version, which will be a bit > more bloated, but no problems. narrowKlass is the result of encoding Klass* with CompressedKlassPointers::encode() which is relative to the compressed base, so if UseCompressedClassPointers is false then the encoding to narrowKlass from some other (CDS?) base isn't valid. using_class_space() above doesn't look wrong for 32 bits. It should return false. With this patch, interface and abstract classes cannot be encoded and decoded to yield a valid compressed narrowKlass, since they're now allocated in the non-class metaspace. Yes, this now a function of which space the Klass resides in. We do crash for these classes in JFR without this change. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/19157#discussion_r1736816371
