On Fri, 28 Nov 2025 21:09:24 GMT, Leonid Mesnik <[email protected]> wrote:
>> The AOT allocates objects while holding lock. The jvmti events can't be
>> posted in such case. The allocation sampling might be just temporary
>> disabled while AOT objects are allocated.
>>
>> I prefer to disable jvmti events for allocation only, not for AOT globally.
>> If there are more events should be generated during AOT initialization, we
>> might want to preserve them and post after initialization is completed.
>>
>> The existing failure could be reproduced by running tests with jvmti stress
>> agent and ZGC enabled. Like
>> make run-test JTREG_JVMTI_STRESS_AGENT=debugger=true
>> TEST=gc/z/TestGarbageCollectorMXBean.java
>>
>> Note:
>> I prelaced NoJvmtiVMObjectAllocMark, it was not used. Also it was incorrect.
>> The
>> NoJvmtiEventsMark should be set even if jvmti events are not enable for this
>> thread. Since jvmti events might be enabled just in the middle of the mark.
>
> Leonid Mesnik has updated the pull request incrementally with one additional
> commit since the last revision:
>
> made jvmti_events_disalber as counter
src/hotspot/share/runtime/javaThread.cpp line 454:
> 452: _is_disable_suspend(false),
> 453: _is_in_java_upcall(false),
> 454: _jvmti_events_disabled(false),
Suggestion:
_jvmti_events_disabled(0),
src/hotspot/share/runtime/javaThread.hpp line 768:
> 766: // - JVMTI is making a Java upcall (_is_in_java_upcall)
> 767: bool should_hide_jvmti_events() const { return
> _is_in_VTMS_transition || _is_disable_suspend
> 768: || _is_in_java_upcall || _jvmti_events_disabled != 0; }
Suggestion:
bool should_hide_jvmti_events() const {
return _is_in_VTMS_transition || _is_disable_suspend || _is_in_java_upcall
|| _jvmti_events_disabled != 0;
}
test/hotspot/jtreg/serviceability/jvmti/events/SampledObjectAlloc/SamplingDuringInit/SamplingDuringInit.java
line 26:
> 24: /**
> 25: * @test
> 26: * @summary Test verify that object allocation sampling is disabled
> during AOT.
Suggestion:
* @summary The test verifies that object allocation sampling is disabled
during AOT.
test/hotspot/jtreg/serviceability/jvmti/events/SampledObjectAlloc/SamplingDuringInit/libSamplingDuringInit.cpp
line 26:
> 24: #include "jvmti.h"
> 25: #include "jvmti_common.hpp"
> 26:
Suggestion:
test/hotspot/jtreg/serviceability/jvmti/events/SampledObjectAlloc/SamplingDuringInit/libSamplingDuringInit.cpp
line 34:
> 32: LOG("Sampled object\n");
> 33: }
> 34:
Suggestion:
test/hotspot/jtreg/serviceability/jvmti/events/SampledObjectAlloc/SamplingDuringInit/libSamplingDuringInit.cpp
line 49:
> 47: return JNI_ERR;
> 48: }
> 49:
Suggestion:
test/hotspot/jtreg/serviceability/jvmti/events/SampledObjectAlloc/SamplingDuringInit/libSamplingDuringInit.cpp
line 67:
> 65: err = jvmti->SetHeapSamplingInterval(10);
> 66: check_jvmti_error(err, "SetHeapSamplingInterval");
> 67:
Suggestion:
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/28544#discussion_r2582743429
PR Review Comment: https://git.openjdk.org/jdk/pull/28544#discussion_r2582750762
PR Review Comment: https://git.openjdk.org/jdk/pull/28544#discussion_r2582754970
PR Review Comment: https://git.openjdk.org/jdk/pull/28544#discussion_r2582755827
PR Review Comment: https://git.openjdk.org/jdk/pull/28544#discussion_r2582756365
PR Review Comment: https://git.openjdk.org/jdk/pull/28544#discussion_r2582756981
PR Review Comment: https://git.openjdk.org/jdk/pull/28544#discussion_r2582759498
