Add force jmethodID experimental feature support

[zhengyu123]

What Does This Do

This PR adds an experimental flag profiling.experimental.ddprof.force_jmethodID to enable ddprof feature that aims to reduce pre-loading jmethodIDs for system classes.

The flag is off (true) by default to preserve current behavior.

Motivation

Preloading all jmethodIDs is proved to be a memory footprint issue. In an extreme case, it consumed 9GB native memory.

ddprof is experimenting a way to lessen dependency on jmethod IDs: none lambda and hidden classes that are loaded by system class loaders (bootstrap, platform and application class loaders), never unloaded. Instead of storing jmethod IDs for the methods of the classes, ddprof stores raw method pointers and resolves at dumping time. Therefore, ddprof does not preload jmethod IDs of none-lambda/hidden classes from those class loaders.

Additional Notes

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Jira ticket: [PROJ-IDENT]

[dd-octo-sts]

🟡 Java Benchmark SLOs — Performance SLO warning (near threshold)

Suite	Status
Startup	🟡 warning

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	14.81 s	14.68 s	[-0.1%; +1.8%] (no difference)
startup:insecure-bank:tracing:Agent	13.63 s	13.70 s	[-1.2%; +0.2%] (no difference)
startup:petclinic:appsec:Agent	16.93 s	16.81 s	[-0.3%; +1.7%] (no difference)
startup:petclinic:iast:Agent	16.75 s	16.99 s	[-2.2%; -0.6%] (maybe better)
startup:petclinic:profiling:Agent	16.72 s	16.86 s	[-2.0%; +0.4%] (no difference)
startup:petclinic:sca:Agent	16.85 s	16.69 s	[+0.1%; +2.0%] (maybe worse)
startup:petclinic:tracing:Agent	15.63 s	16.11 s	[-7.1%; +1.1%] (no difference)

Commit: 94654d01 · CI Pipeline · Benchmarking Platform UI

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[Copilot]

Pull request overview

Adds an experimental profiling configuration flag to control ddprof’s “force jmethodID preloading” behavior, aiming to reduce native memory usage by allowing jmethodID preloading to be disabled for eligible classes while preserving current behavior by default.

Changes:

• Added a new profiling config key + default for profiling.experimental.ddprof.force_jmethodID.
• Wired the flag into ddprof start command generation (emit fjmethodid=false when disabled).
• Exposed the flag in supported-config metadata and in the profiler flare configuration output.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
metadata/supported-configurations.json	Registers the new env var metadata entry for the experimental ddprof flag.
dd-trace-api/src/main/java/datadog/trace/api/config/ProfilingConfig.java	Introduces the public config constant and default value for the new flag.
dd-java-agent/agent-profiling/profiling-ddprof/src/main/java/com/datadog/profiling/ddprof/DatadogProfilerConfig.java	Adds a helper accessor to read the boolean config from ConfigProvider.
dd-java-agent/agent-profiling/profiling-ddprof/src/main/java/com/datadog/profiling/ddprof/DatadogProfiler.java	Appends the ddprof command option when the flag is set to disable forcing jmethodID preloading.
dd-java-agent/agent-profiling/profiling-controller/src/main/java/com/datadog/profiling/controller/ProfilerFlareReporter.java	Includes the new flag in flare-reported profiler configuration output.

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.