Metaspace leak with instrumentation.retransform
Jean-Philippe Bempel
jean-philippe.bempel at datadoghq.com
Wed May 24 09:26:20 UTC 2023
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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