On Wed, 7 Jan 2026 06:09:19 GMT, Yasumasa Suenaga <[email protected]> wrote:
>> We can extract heap dump from coredump with `jhsdb jmap --binaryheap`, but >> it does not contain `HPROF_GC_ROOT_JAVA_FRAME`. It means we cannot detect >> leaked object on thread stack. >> >> I attached 2 images which I saw on Eclipse Memory Analyzer Tool (MAT). Heap >> dumps were created following options: >> >> >> -Xmx256m -XX:+CrashOnOutOfMemoryError -XX:+HeapDumpOnOutOfMemoryError >> >> >> <img width="801" height="127" alt="heapdumponoutofmemoryerror" >> src="https://github.com/user-attachments/assets/7293e909-1c73-465a-a57c-2102251ba463"; >> /> >> >> This image shows "thread overview" from the heapdump by >> `-XX:+HeapDumpOnOutOfMemoryError`. It reports `OOME.main` has large retained >> heap. >> >> <img width="825" height="87" alt="from-core" >> src="https://github.com/user-attachments/assets/15fd3d86-76f9-452c-8103-45b631165238"; >> /> >> >> On the other hand, this image extracted by `jhsdb jmap --binaryheap` does >> not report it - leaked object is reported as unreachable objects. >> >> heapDump.cpp in HotSpot dumps `HPROF_GC_ROOT_JAVA_FRAME` for each Java >> frames. SA should do that. >> >> Essensially, we need to apply the fix in >> https://github.com/openjdk/jdk/commit/290c5bae15154a9df1c2f3cfd90ebd6de1a20210 >> , however it fails with exception due to access `oop` in out of range. We >> need to fix the number of objects in expression stack like HotSpot. I fixed >> it in >> https://github.com/openjdk/jdk/commit/0697df16e2aa3f3ace7d82da0a263663fba2e2df >> . And also I saw error relates to `invokedynamic` because ConstantPool in >> SA has not followed curre t HotSpot implementation. So I fixed it in >> https://github.com/openjdk/jdk/pull/29058/commits/a9c9e6c9a345aeb4b2773fd0402342741d180f4d >> . >> >> This change works fine with both interpreter and `-Xcomp`. > > Yasumasa Suenaga has updated the pull request incrementally with two > additional commits since the last revision: > > - Update copyright year in ConstantPool.java > - Update ClhsdbDumpheap to verify HPROF_GC_ROOT_JAVA_FRAME PING: Can I get Reviewers? Thanks! ------------- PR Comment: https://git.openjdk.org/jdk/pull/29058#issuecomment-3747327414
