RFR: 8316694: Implement relocation of nmethod within CodeCache [v32]

[Chad Rakoczy]

On Wed, 2 Jul 2025 20:43:35 GMT, Chad Rakoczy <duke at openjdk.org> wrote:

>> src/hotspot/share/code/nmethod.cpp line 1653:
>> 
>>> 1651:       }
>>> 1652:     }
>>> 1653:   }
>> 
>> Do we need this code? Shouldn't missing trampolined be caught during fixing call sites?
>
> If fixing call sites fails (like in the event of a missing trampoline) an assert will fail and the JVM will crash. I suppose it could be updated to abandon the relocation if that happens but that would require `fix_relocation_after_move` to return if it succeeded and proper handling by the caller.

This is only an issue because Hotspot reduces the branch range for debug builds on aarch64 and Graal doesn't. If we're going to handle this case I think we should fail fast but it does raise the question of what should actually be done in this situation

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/23573#discussion_r2180940888