High CPU Usage by TruffleCompilerThread

[dandelion2]

Describe GraalVM and your environment :

• GraalVM version or commit id if built from source: 22.3.3
• CE or EE: CE
• JDK version: JDK11
• OS and OS Version: ubuntu 20.04
• Architecture: amd64
• The output of java -Xinternalversion:

 **OpenJDK 64-Bit Server VM (11.0.20+8-jvmci-22.3-b22) for linux-amd64 JRE (11.0.20+8-jvmci-22.3-b22), built on Jul 19 2023 20:41:46 by "buildslave" with gcc 8.2.0**

Have you verified this issue still happens when using the latest snapshot?
You can find snapshot builds here: https://github.com/graalvm/graalvm-ce-dev-builds/releases

Describe the issue
During concurrent testing (100 threads), it was found that the CPU usage was excessively high, reaching nearly 300% on a 4-core CPU. Analysis revealed that three TruffleCompilerThread threads were responsible for this high usage. In the stress test code, both the context and the compilation results were cached to reduce redundant compilation.

Code snippet or code repository that reproduces the issue

Context context = contextManager.getContext(script, type);
Value value = context.getBindings("js").getMember(name);
if (value == null){
	context.eval("js",script);
	value = context.getBindings("js").getMember(name);
}
Object obj = value.execute(arguments).as(Object.class);
Object res = JSON.parse(JSON.toJSONString(obj));
return res;

Additional context
Current Invocation Method：java -jar -Dpolyglot.engine.OptimizationLevel=0 xxx.jar

Details

    Threads Total: 327, NEW: 0, RUNNABLE: 55, BLOCKED: 4, WAITING: 80, TIMED_WAITING: 164, TERMINATED: 0, Internal threads: 24                                                          
ID      NAME                                         GROUP                 PRIORITY       STATE          %CPU           DELTA_TIME     TIME           INTERRUPTED    DAEMON         
429     TruffleCompilerThread-429                    main                  10             RUNNABLE       99.71          0.204          13:22.927      false          true           
387     TruffleCompilerThread-387                    main                  10             RUNNABLE       99.59          0.204          13:22.452      false          true           
430     TruffleCompilerThread-430                    main                  10             RUNNABLE       98.72          0.202          13:22.234      false          true           

[selhagani]

Hi @dandelion2,

Thank you for reaching out to us about this.
Could you please try retesting using the latest version of GraalVM? You can find it using this link: https://github.com/graalvm/graalvm-ce-builds/releases/

[chumer]

Note -Dpolyglot.engine.OptimizationLevel=0 is not a valid option and does nothing. I am surprised it boots at all with this option.

Also, would you mind sharing a fully runnable example? Without the script executing we will not be able to reproduce this.

[dandelion2]

Hi @dandelion2,

Thank you for reaching out to us about this. Could you please try retesting using the latest version of GraalVM? You can find it using this link: https://github.com/graalvm/graalvm-ce-builds/releases/

Hi @dandelion2,

Thank you for reaching out to us about this. Could you please try retesting using the latest version of GraalVM? You can find it using this link: https://github.com/graalvm/graalvm-ce-builds/releases/

Thank you for your suggestions. Due to certain reasons, we are not able to upgrade at the moment. Could you tell me what optimization parameters are available for multi-threaded script compilation in GraalVM Community Edition 22.3?

[chumer]

-Dpolyglot.engine.OptimizationLevel=0 does not exist in any version, did your LLM generate this suggestion?

We have lots of options documented here:
https://github.com/oracle/graal/blob/master/truffle/docs/Options.md#expert-engine-options

You can use:
-Dpolyglot.engine.Compilation=false to disable compilation entirely
and
-Dpolyglot.engine.Mode=latency for a more latency focused run-mode.

[dandelion2]

-Dpolyglot.engine.OptimizationLevel=0 does not exist in any version, did your LLM generate this suggestion?

We have lots of options documented here: https://github.com/oracle/graal/blob/master/truffle/docs/Options.md#expert-engine-options

You can use: -Dpolyglot.engine.Compilation=false to disable compilation entirely and -Dpolyglot.engine.Mode=latency for a more latency focused run-mode.

Thank you, we will give it a try.