Analysis Date | JDK | Operating System | CPU Architecture | Debug JVM? |
---|---|---|---|---|
2025-08-21 | OpenJDK17 | Linux | x86 | N |
Results
Switches Identified
Switch Analysis
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
rs | reduce use of OS signals by Java/VM (see documentation) | : | ||
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
PrintFlagsFinal | boolean | Print all VM flags after argument and ergonomic processing | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseCompressedOops | boolean | Use 32-bit object references in 64-bit VM. lp64_product means flag is always constant in 32 bit VM |
false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
HeapDumpOnOutOfMemoryError | boolean | Dump heap to file when java.lang.OutOfMemoryError is thrown from JVM |
false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
HeapDumpPath | string | When HeapDumpOnOutOfMemoryError is on, the path (filename or directory) of the dump file (defaults to java_pid<pid>.hprof in the working directory) |
NULL | /opt/cgm/g3_8180_uke13/instance1/tomcat-9.0/dumpfiles |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseG1GC | boolean | Use the Garbage-First garbage collector | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
AlwaysPreTouch | boolean | Force all freshly committed pages to be pre-touched | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
ScavengeBeforeFullGC | boolean | Scavenge youngest generation before each full GC. | true | true |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK23. Expired in OpenJDK24. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
DisableExplicitGC | boolean | Ignore calls to System.gc() | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseStringDeduplication | boolean | Use string deduplication | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
ms | <size> | set initial Java heap size | 64G | |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
mx | <size> | set maximum Java heap size | 64G | |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
log | <opts> | Configure or enable logging with the Java Virtual Machine (JVM) unified logging framework. Use -Xlog:help for details. |
codecache=info,codecache+sweep*=trace,class+unload,class+load,os+thread,safepoint,gc*,stringdedup*,gc+ergo=trace,gc+age=trace,gc+phases=trace,gc+humongous=trace,jit+compilation=debug:file=/opt/cgm/g3_8180_uke13/instance1/tomcat-9.0/logs/gc.log:level,tags,time,uptime:filesize=104857600,filecount=5 | |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CrashOnOutOfMemoryError | boolean | JVM aborts, producing an error log and core/mini dump, on the first occurrence of an out-of-memory error thrown from JVM |
false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
InitiatingHeapOccupancyPercent | int | The percent occupancy (IHOP) of the current old generation capacity above which a concurrent mark cycle will be initiated Its value may change over time if adaptive IHOP is enabled, otherwise the value remains constant. In the latter case a value of 0 will result as frequent as possible concurrent marking cycles. A value of 100 disables concurrent marking. Fragmentation waste in the old generation is not considered free space in this calculation. (G1 collector only) |
45 in range(0, 100) | 70 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
ParallelGCThreads | uint | Number of parallel threads parallel gc will use | 0 | 10 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseLargePages | boolean | Use large page memory | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseTransparentHugePages | boolean | Use MADV_HUGEPAGE for large pages | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UnlockExperimentalVMOptions | boolean | Enable normal processing of flags relating to experimental features |
false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
G1NewSizePercent | int | Percentage (0-100) of the heap size to use as default minimum young gen size. |
5 in range(0, 100) | 50 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
MetaspaceSize | size_t | Initial threshold (in bytes) at which a garbage collection is done to reduce Metaspace usage |
NOT_LP64(16 * M) LP64_ONLY(21 * M) | 1024m |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
MaxMetaspaceSize | size_t | Maximum size of Metaspaces (in bytes) | max_uintx | 3072m |
Analysis | OK |
Name | Type | Description | Default Value | Your Value | ||||
---|---|---|---|---|---|---|---|---|
ReservedCodeCacheSize | int | Reserved code cache size (in bytes) - maximum code cache size |
|
512m | ||||
Analysis | OK |