RFR: 8355003: Implement Ahead-of-Time Method Profiling [v13]

[Igor Veresov]

On Tue, 6 May 2025 18:48:03 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> Igor Veresov has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 43 commits:
>> 
>>  - Merge branch 'master' into pp2
>>  - Fix compile
>>  - Fix additional issues
>>  - Make sure command line flags that affect MDO layout are consistent
>>  - Fix semantics change from the previous commit
>>  - Port 8355915: [leyden] Crash in MDO clearing the unloaded array type
>>  - Fix flag behavior
>>  - Fix log tags
>>  - Remove the proxy class counter
>>  - Address review comments part 2
>>  - ... and 33 more: https://git.openjdk.org/jdk/compare/e09d2e27...7d22a42a
>
> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/memory/FileMapInfo.java line 129:
> 
>> 127:     metadataTypeArray[5] = db.lookupType("InstanceStackChunkKlass");
>> 128:     metadataTypeArray[6] = db.lookupType("Method");
>> 129:     metadataTypeArray[9] = db.lookupType("MethodData");
> 
> It looks like MethodData inheriting from Metadata is not a new change, but has always been the case. I'm surprised this didn't cause any test failures before your changes. Did you end up with test failures after your changes?

Honestly I don't remember, I think @iklam did these changes.

> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/Threads.java line 154:
> 
>> 152:         if (!VM.getVM().isCore()) {
>> 153:             virtualConstructor.addMapping("CompilerThread", CompilerThread.class);
>> 154:             virtualConstructor.addMapping("TrainingReplayThread", TrainingReplayThread.class);
> 
> The new SA TrainingReplayThread class is not needed since it only overrides isHiddenFromExternalView() to return true. You can instead use HiddenJavaThread.class here.

Done

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

PR Review Comment: https://git.openjdk.org/jdk/pull/24886#discussion_r2076373507
PR Review Comment: https://git.openjdk.org/jdk/pull/24886#discussion_r2076369998