Metaspace leak with instrumentation.retransform

coleen.phillimore at oracle.com coleen.phillimore at oracle.com
Wed May 24 12:53:21 UTC 2023


You could also try -Xlog:redefine+class+iklass+purge=trace

It might think the previous versions of these methods are still alive.

Coleen

On 5/24/23 5:26 AM, Jean-Philippe Bempel wrote:
> Here the JBS: https://bugs.openjdk.org/browse/JDK-8308762 with the
> output of "-Xlog:metaspace=trace"
>
> Thanks
> Jean-Philippe Bempel
>
> On Wed, May 24, 2023 at 9:10 AM Thomas Stüfe <thomas.stuefe at gmail.com> wrote:
>> Yes, that's the space for the old bytecode sitting around waiting to be re-used:
>>
>> ` Deallocated from chunks in use:    127.36 MB (>99%) (11785 blocks) `
>>
>> It would be nice if you could open a JBS issue and attach the program and a log produced with "-Xlog:metaspace=trace"; you may have to zip the thing if it gets too large.
>>
>>
>>
>> On Wed, May 24, 2023 at 9:06 AM Jean-Philippe Bempel <jean-philippe.bempel at datadoghq.com> wrote:
>>> On Wed, May 24, 2023 at 8:21 AM Thomas Stüfe <thomas.stuefe at gmail.com> wrote:
>>>>
>>>> My first thought was that this is not a leak but a case of class redefinition, where the bytecode is rewritten. The space for the old bytecode gets salvaged and would be re-used for metaspace allocations from the same loader, save that said re-use never happens for some reason. The output of "jcmd VM.metaspace" at the end of the program run would be helpful too.
>>>>
>>> Here the output of VM.metaspace:
>>>
>>> $ jcmd 6940 VM.metaspace
>>> 6940:
>>>
>>> Total Usage - 6 loaders, 809 classes (776 shared):
>>>    Non-Class: 2605 chunks,    131.55 MB capacity,  127.87 MB ( 97%)
>>> committed,   127.83 MB ( 97%) used,    37.94 KB ( <1%) free,     8
>>> bytes ( <1%) waste , deallocated: 11783 blocks with 127.36 MB
>>>        Class:    8 chunks,    266.00 KB capacity,   74.00 KB ( 28%)
>>> committed,    17.48 KB (  7%) used,    56.52 KB ( 21%) free,     0
>>> bytes (  0%) waste , deallocated: 2 blocks with 512 bytes
>>>         Both: 2613 chunks,    131.81 MB capacity,  127.94 MB ( 97%)
>>> committed,   127.85 MB ( 97%) used,    94.45 KB ( <1%) free,     8
>>> bytes ( <1%) waste , deallocated: 11785 blocks with 127.36 MB
>>>
>>>
>>> Virtual space:
>>>    Non-class space:      192.00 MB reserved,     127.88 MB ( 67%)
>>> committed,  3 nodes.
>>>        Class space:      104.00 MB reserved,     128.00 KB ( <1%)
>>> committed,  1 nodes.
>>>               Both:      296.00 MB reserved,     128.00 MB ( 43%) committed.
>>>
>>>
>>> Chunk freelists:
>>>     Non-Class:
>>>
>>>    4m: (none)
>>>    2m: (none)
>>>    1m: (none)
>>> 512k: (none)
>>> 256k:    2, capacity=512.00 KB, committed=0 bytes (  0%)
>>> 128k:    2, capacity=256.00 KB, committed=0 bytes (  0%)
>>>   64k:    2, capacity=128.00 KB, committed=0 bytes (  0%)
>>>   32k: (none)
>>>   16k: (none)
>>>    8k: (none)
>>>    4k:    2, capacity=8.00 KB, committed=8.00 KB (100%)
>>>    2k:    6, capacity=12.00 KB, committed=12.00 KB (100%)
>>>    1k: (none)
>>> Total word size: 916.00 KB, committed: 20.00 KB (  2%)
>>>
>>>         Class:
>>>
>>>    4m: (none)
>>>    2m:    1, capacity=2.00 MB, committed=0 bytes (  0%)
>>>    1m:    1, capacity=1.00 MB, committed=0 bytes (  0%)
>>> 512k:    1, capacity=512.00 KB, committed=0 bytes (  0%)
>>> 256k: (none)
>>> 128k:    1, capacity=128.00 KB, committed=0 bytes (  0%)
>>>   64k:    1, capacity=64.00 KB, committed=0 bytes (  0%)
>>>   32k:    1, capacity=32.00 KB, committed=0 bytes (  0%)
>>>   16k:    1, capacity=16.00 KB, committed=0 bytes (  0%)
>>>    8k: (none)
>>>    4k: (none)
>>>    2k:    1, capacity=2.00 KB, committed=2.00 KB (100%)
>>>    1k:    3, capacity=3.00 KB, committed=3.00 KB (100%)
>>> Total word size: 3.74 MB, committed: 5.00 KB ( <1%)
>>>
>>>          Both:
>>>
>>>    4m: (none)
>>>    2m:    1, capacity=2.00 MB, committed=0 bytes (  0%)
>>>    1m:    1, capacity=1.00 MB, committed=0 bytes (  0%)
>>> 512k:    1, capacity=512.00 KB, committed=0 bytes (  0%)
>>> 256k:    2, capacity=512.00 KB, committed=0 bytes (  0%)
>>> 128k:    3, capacity=384.00 KB, committed=0 bytes (  0%)
>>>   64k:    3, capacity=192.00 KB, committed=0 bytes (  0%)
>>>   32k:    1, capacity=32.00 KB, committed=0 bytes (  0%)
>>>   16k:    1, capacity=16.00 KB, committed=0 bytes (  0%)
>>>    8k: (none)
>>>    4k:    2, capacity=8.00 KB, committed=8.00 KB (100%)
>>>    2k:    7, capacity=14.00 KB, committed=14.00 KB (100%)
>>>    1k:    3, capacity=3.00 KB, committed=3.00 KB (100%)
>>> Total word size: 4.63 MB, committed: 25.00 KB ( <1%)
>>>
>>>
>>>
>>> Waste (unused committed space):(percentages refer to total committed
>>> size 128.00 MB):
>>>          Waste in chunks in use:      8 bytes ( <1%)
>>>          Free in chunks in use:     94.45 KB ( <1%)
>>>                  In free chunks:     25.00 KB ( <1%)
>>> Deallocated from chunks in use:    127.36 MB (>99%) (11785 blocks)
>>>                         -total-:    127.48 MB (>99%)
>>>
>>> chunk header pool: 2632 items, 189.33 KB.
>>>
>>> Internal statistics:
>>>
>>> num_allocs_failed_limit: 23.
>>> num_arena_births: 22.
>>> num_arena_deaths: 10.
>>> num_vsnodes_births: 4.
>>> num_vsnodes_deaths: 0.
>>> num_space_committed: 2048.
>>> num_space_uncommitted: 0.
>>> num_chunks_returned_to_freelist: 33.
>>> num_chunks_taken_from_freelist: 2624.
>>> num_chunk_merges: 11.
>>> num_chunk_splits: 1456.
>>> num_chunks_enlarged: 276.
>>> num_inconsistent_stats: 0.
>>>
>>>
>>> Settings:
>>> MaxMetaspaceSize: 128.00 MB
>>> CompressedClassSpaceSize: 104.00 MB
>>> Initial GC threshold: 21.00 MB
>>> Current GC threshold: 128.00 MB
>>> CDS: on
>>> MetaspaceReclaimPolicy: balanced
>>>   - commit_granule_bytes: 65536.
>>>   - commit_granule_words: 8192.
>>>   - virtual_space_node_default_size: 8388608.
>>>   - enlarge_chunks_in_place: 1.
>>>   - new_chunks_are_fully_committed: 0.
>>>   - uncommit_free_chunks: 1.
>>>   - use_allocation_guard: 0.
>>>
>>> Also I have run it with -XX:+CrashOnOutOfMemoryError to have  stacktrace:
>>> Stack: [0x00007f8d9c400000,0x00007f8d9c500000],
>>> sp=0x00007f8d9c4fdb80,  free space=1014k
>>> Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
>>> V  [libjvm.so+0xf9f4e7]  VMError::report_and_die(int, char const*,
>>> char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*,
>>> char const*, int, unsigned long)+0x197  (debug.cpp:368)
>>> V  [libjvm.so+0x672eab]  report_fatal(VMErrorType, char const*, int,
>>> char const*, ...)+0x12b
>>> V  [libjvm.so+0x67315d]  report_java_out_of_memory(char const*)+0xed
>>> V  [libjvm.so+0xc238d0]
>>> Metaspace::report_metadata_oome(ClassLoaderData*, unsigned long,
>>> MetaspaceObj::Type, Metaspace::MetadataType, JavaThread*)+0x260
>>> V  [libjvm.so+0xc23b33]  Metaspace::allocate(ClassLoaderData*,
>>> unsigned long, MetaspaceObj::Type, JavaThread*)+0x133
>>> V  [libjvm.so+0x650e8b]  ConstantPool::allocate(ClassLoaderData*, int,
>>> JavaThread*)+0x7b
>>> V  [libjvm.so+0xae518c]
>>> VM_RedefineClasses::merge_cp_and_rewrite(InstanceKlass*,
>>> InstanceKlass*, JavaThread*)+0x4c
>>> V  [libjvm.so+0xae6e6d]  VM_RedefineClasses::load_new_class_versions()
>>> [clone .part.0]+0x34d
>>> V  [libjvm.so+0xae794f]  VM_RedefineClasses::doit_prologue()+0x17f
>>> V  [libjvm.so+0xfa8ee0]  VMThread::execute(VM_Operation*)+0x40
>>> V  [libjvm.so+0xab416f]  JvmtiEnv::RetransformClasses(int, _jclass*
>>> const*)+0x2bf
>>> V  [libjvm.so+0xa5f04c]  jvmti_RetransformClasses+0xfc
>>> C  [libinstrument.so+0x4e86]  retransformClasses+0x1b6
>>> J 182  sun.instrument.InstrumentationImpl.retransformClasses0(J[Ljava/lang/Class;)V
>>> java.instrument at 20.0.1 (0 bytes) @ 0x00007f8d886d8077
>>> [0x00007f8d886d7fa0+0x00000000000000d7]
>>> J 181 c1 sun.instrument.InstrumentationImpl.retransformClasses([Ljava/lang/Class;)V
>>> java.instrument at 20.0.1 (33 bytes) @ 0x00007f8d80c29a5c
>>> [0x00007f8d80c29860+0x00000000000001fc]
>>> j  Agent.retransformLoop(Ljava/lang/instrument/Instrumentation;Ljava/lang/String;)V+82
>>> j  Agent.lambda$premain$0(Ljava/lang/instrument/Instrumentation;Ljava/lang/String;)V+2
>>> j  Agent$$Lambda$14+0x0000000801002c00.run()V+8
>>> j  java.lang.Thread.runWith(Ljava/lang/Object;Ljava/lang/Runnable;)V+5
>>> java.base at 20.0.1
>>> j  java.lang.Thread.run()V+19 java.base at 20.0.1
>>> v  ~StubRoutines::call_stub 0x00007f8d88138cc6
>>> V  [libjvm.so+0x8c9c85]  JavaCalls::call_helper(JavaValue*,
>>> methodHandle const&, JavaCallArguments*, JavaThread*)+0x315
>>> V  [libjvm.so+0x8cb5f2]  JavaCalls::call_virtual(JavaValue*, Handle,
>>> Klass*, Symbol*, Symbol*, JavaThread*)+0x1d2
>>> V  [libjvm.so+0x99debe]  thread_entry(JavaThread*, JavaThread*)+0x8e
>>> V  [libjvm.so+0x8e1578]  JavaThread::thread_main_inner() [clone .part.0]+0xb8
>>> V  [libjvm.so+0xf18736]  Thread::call_run()+0xa6
>>> V  [libjvm.so+0xcae8d8]  thread_native_entry(Thread*)+0xd8
>>> Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
>>> J 182  sun.instrument.InstrumentationImpl.retransformClasses0(J[Ljava/lang/Class;)V
>>> java.instrument at 20.0.1 (0 bytes) @ 0x00007f8d886d8004
>>> [0x00007f8d886d7fa0+0x0000000000000064]
>>> J 181 c1 sun.instrument.InstrumentationImpl.retransformClasses([Ljava/lang/Class;)V
>>> java.instrument at 20.0.1 (33 bytes) @ 0x00007f8d80c29a5c
>>> [0x00007f8d80c29860+0x00000000000001fc]
>>> j  Agent.retransformLoop(Ljava/lang/instrument/Instrumentation;Ljava/lang/String;)V+82
>>> j  Agent.lambda$premain$0(Ljava/lang/instrument/Instrumentation;Ljava/lang/String;)V+2
>>> j  Agent$$Lambda$14+0x0000000801002c00.run()V+8
>>> j  java.lang.Thread.runWith(Ljava/lang/Object;Ljava/lang/Runnable;)V+5
>>> java.base at 20.0.1
>>> j  java.lang.Thread.run()V+19 java.base at 20.0.1
>>> v  ~StubRoutines::call_stub 0x00007f8d88138cc6
>>>
>>> I will continue to investigate on my side, but If you need more
>>> details, please ask.
>>> Jean-Philippe Bempel



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