DefaultJvmMetadataDetector#getMetadataFromInstallation misses Xmx, so the JVM might allocate significant amount of memory

[vlsi]

Expected Behavior

Gradle builds should not consume excessive amounts of memory.
See

gradle/subprojects/jvm-services/src/main/java/org/gradle/internal/jvm/inspection/DefaultJvmMetadataDetector.java

Lines 99 to 112 in 07cd5f4

	private JvmInstallationMetadata getMetadataFromInstallation(File jdkPath) {
	File tmpDir = temporaryFileProvider.createTemporaryDirectory("jvm", "probe");
	File probe = writeProbeClass(tmpDir);
	ExecHandleBuilder exec = execHandleFactory.newExec();
	exec.setWorkingDir(probe.getParentFile());
	exec.executable(javaExecutable(jdkPath));
	try {
	ByteArrayOutputStream out = new ByteArrayOutputStream();
	ByteArrayOutputStream errorOutput = new ByteArrayOutputStream();
	String mainClassname = Files.getNameWithoutExtension(probe.getName());
	exec.args("-cp", ".", mainClassname);
	exec.setStandardOutput(out);
	exec.setErrorOutput(errorOutput);
	exec.setIgnoreExitValue(true);

Current Behavior

Gradle spawns .../bin/java -cp . JavaProbe without -Xmx

Context (optional)

See sample.
Java with defaults "commits" 1.15G ram while Java with -Xmx32m commits 0.11G only.

$ java -XX:NativeMemoryTracking=summary -XX:+UnlockDiagnosticVMOptions -XX:+PrintNMTStatistics -version

openjdk version "17.0.7" 2023-04-18 LTS
OpenJDK Runtime Environment (build 17.0.7+7-LTS)
OpenJDK 64-Bit Server VM (build 17.0.7+7-LTS, mixed mode, sharing)

Native Memory Tracking:

Total: reserved=19313204297, committed=1235819593
       malloc: 22932553 #4973
       mmap:   reserved=19290271744, committed=1212887040

-                 Java Heap (reserved=17179869184, committed=1090519040)
                            (mmap: reserved=17179869184, committed=1090519040)

-                     Class (reserved=1073812158, committed=135870)
                            (classes #447)
                            (  instance classes #362, array classes #85)
                            (malloc=70334 #465)
                            (mmap: reserved=1073741824, committed=65536)
                            (  Metadata:   )
                            (    reserved=67108864, committed=65536)
                            (    used=52576)
                            (    waste=12960 =19,78%)
                            (  Class space:)
                            (    reserved=1073741824, committed=65536)
                            (    used=1624)
                            (    waste=63912 =97,52%)

-                    Thread (reserved=27465584, committed=27465584)
                            (thread #13)
                            (stack: reserved=27422720, committed=27422720)
                            (malloc=24432 #106)
                            (arena=18432 #32)

-                      Code (reserved=253671496, committed=7796808)
                            (malloc=30792 #535)
                            (mmap: reserved=253640704, committed=7766016)

-                        GC (reserved=692389522, committed=95323794)
                            (malloc=20743826 #588)
                            (mmap: reserved=671645696, committed=74579968)

-                  Compiler (reserved=170808, committed=170808)
                            (malloc=2248 #19)
                            (arena=168560 #5)

-                  Internal (reserved=177265, committed=177265)
                            (malloc=144497 #1115)
                            (mmap: reserved=32768, committed=32768)

-                    Symbol (reserved=1157952, committed=1157952)
                            (malloc=789312 #36)
                            (arena=368640 #1)

-    Native Memory Tracking (reserved=83624, committed=83624)
                            (malloc=4040 #55)
                            (tracking overhead=79584)

-        Shared class space (reserved=16777216, committed=12402688)
                            (mmap: reserved=16777216, committed=12402688)

-               Arena Chunk (reserved=375088, committed=375088)
                            (malloc=375088)

-                   Tracing (reserved=313, committed=313)
                            (malloc=313 #9)

-                 Arguments (reserved=171, committed=171)
                            (malloc=171 #5)

-                    Module (reserved=13800, committed=13800)
                            (malloc=13800 #401)

-                 Safepoint (reserved=32768, committed=32768)
                            (mmap: reserved=32768, committed=32768)

-           Synchronization (reserved=86804, committed=86804)
                            (malloc=86804 #1559)

-            Serviceability (reserved=576, committed=576)
                            (malloc=576 #6)

-                 Metaspace (reserved=67118944, committed=75616)
                            (malloc=10080 #6)
                            (mmap: reserved=67108864, committed=65536)

-      String Deduplication (reserved=608, committed=608)
                            (malloc=608 #8)

-           Object Monitors (reserved=416, committed=416)
                            (malloc=416 #2)

The same with -Xmx32m:

% java -XX:NativeMemoryTracking=summary -XX:+UnlockDiagnosticVMOptions -XX:+PrintNMTStatistics -Xmx32m -version
openjdk version "17.0.7" 2023-04-18 LTS
OpenJDK Runtime Environment (build 17.0.7+7-LTS)
OpenJDK 64-Bit Server VM (build 17.0.7+7-LTS, mixed mode, sharing)

Native Memory Tracking:

Total: reserved=1528320534, committed=137351702
       malloc: 21193238 #4086
       mmap:   reserved=1507127296, committed=116158464

-                 Java Heap (reserved=33554432, committed=33554432)
                            (mmap: reserved=33554432, committed=33554432)

-                     Class (reserved=1073812158, committed=135870)
                            (classes #447)
                            (  instance classes #362, array classes #85)
                            (malloc=70334 #465)
                            (mmap: reserved=1073741824, committed=65536)
                            (  Metadata:   )
                            (    reserved=67108864, committed=65536)
                            (    used=52576)
                            (    waste=12960 =19,78%)
                            (  Class space:)
                            (    reserved=1073741824, committed=65536)
                            (    used=1624)
                            (    waste=63912 =97,52%)

-                    Thread (reserved=27465584, committed=27465584)
                            (thread #13)
                            (stack: reserved=27422720, committed=27422720)
                            (malloc=24432 #106)
                            (arena=18432 #32)

-                      Code (reserved=253671352, committed=7796664)
                            (malloc=30648 #529)
                            (mmap: reserved=253640704, committed=7766016)

-                        GC (reserved=53962202, committed=53962202)
                            (malloc=19146202 #294)
                            (mmap: reserved=34816000, committed=34816000)

-                  Compiler (reserved=382296, committed=382296)
                            (malloc=2248 #19)
                            (arena=380048 #13)

-                  Internal (reserved=172182, committed=172182)
                            (malloc=139414 #922)
                            (mmap: reserved=32768, committed=32768)

-                    Symbol (reserved=1157952, committed=1157952)
                            (malloc=789312 #36)
                            (arena=368640 #1)

-    Native Memory Tracking (reserved=69096, committed=69096)
                            (malloc=3704 #49)
                            (tracking overhead=65392)

-        Shared class space (reserved=16777216, committed=12402688)
                            (mmap: reserved=16777216, committed=12402688)

-               Arena Chunk (reserved=66368, committed=66368)
                            (malloc=66368)

-                   Tracing (reserved=313, committed=313)
                            (malloc=313 #9)

-                 Arguments (reserved=171, committed=171)
                            (malloc=171 #5)

-                    Module (reserved=13800, committed=13800)
                            (malloc=13800 #401)

-                 Safepoint (reserved=32768, committed=32768)
                            (mmap: reserved=32768, committed=32768)

-           Synchronization (reserved=62100, committed=62100)
                            (malloc=62100 #1173)

-            Serviceability (reserved=576, committed=576)
                            (malloc=576 #6)

-                 Metaspace (reserved=67118944, committed=75616)
                            (malloc=10080 #6)
                            (mmap: reserved=67108864, committed=65536)

-      String Deduplication (reserved=608, committed=608)
                            (malloc=608 #8)

-           Object Monitors (reserved=416, committed=416)
                            (malloc=416 #2)

Steps to Reproduce

Run Gradle build with toolchains.

Gradle version

8.1.1

Build scan URL (optional)

No response

Your Environment (optional)

No response

[ov7a]

Thank you for providing a valid reproducer.

The issue is in the backlog of the relevant team, but this area of Gradle is currently not a focus one, so it might take a while before a fix is made.

[ov7a]

This issue is a good choice for first-time contributors to Gradle, it is actionable and ready for contribution.

See CONTRIBUTING.md for more information.

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Let's pass Xmx and Xms with 32M as default.