RFR: 8306591: SA and hotspot generate different hprof records for GC roots [v3]

[David Holmes]

On Mon, 23 Feb 2026 07:15:07 GMT, Yasumasa Suenaga <ysuenaga at openjdk.org> wrote:

>> We can extract heapdump from coredump via `jhsdb jmap --binaryheap`. However GC roots for system classes (`HPROF_GC_ROOT_STICKY_CLASS`) are not available i it even though heapdump from HotSpot contains.
>> 
>> SA should generate `HPROF_GC_ROOT_STICKY_CLASS` into heapdump.
>
> Yasumasa Suenaga has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/hotspot/share/runtime/vmStructs.cpp
>   
>   Co-authored-by: David Holmes <62092539+dholmes-ora at users.noreply.github.com>

src/hotspot/share/runtime/vmStructs.cpp line 433:

> 431:   static_field(ClassLoaderData,                 _the_null_class_loader_data,                  ClassLoaderData*)                      \
> 432:                                                                                                                                      \
> 433:   volatile_static_field(ClassLoaderDataGraph, _head,                                          ClassLoaderData*)                      \

Sorry the alignment is still off-by-one

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PR Review Comment: https://git.openjdk.org/jdk/pull/29781#discussion_r2839665630