JaCoLine - Viewing Historical Command Line #6632
| Analysis Date | JDK | Operating System | CPU Architecture | Debug JVM? |
|---|---|---|---|---|
| 2023-01-13 | OpenJDK17 | Linux | x86 | N |
Results
Switches Identified
Switch Analysis
| 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 |
|---|---|---|---|---|
| DisableExplicitGC | boolean | Ignore calls to System.gc() | false | true |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| EliminateLocks | boolean | Coarsen locks when possible | true | true |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| ExitOnOutOfMemoryError | boolean | JVM exits on the first occurrence of an out-of-memory error thrown from JVM |
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 |
|---|---|---|---|---|
| OptimizeStringConcat | boolean | Optimize the construction of Strings by StringBuilder | true | true |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| ParallelRefProcEnabled | boolean | Enable parallel reference processing whenever possible | false | true |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| PerfDisableSharedMem | boolean | Store performance data in standard memory | 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 | ||||
|---|---|---|---|---|---|---|---|---|
| TieredCompilation | boolean | Enable tiered compilation |
|
true | ||||
| 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 |
|---|---|---|---|---|
| UseStringDeduplication | boolean | Use string deduplication | false | true |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| UseZGC | boolean | Use the Z garbage collector | false | true |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| MaxMetaspaceExpansion | size_t | The maximum expansion of Metaspace without full GC (in bytes) | ScaleForWordSize(4*M) in range(0, max_uintx) | 32m |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| MaxMetaspaceFreeRatio | int | The maximum percentage of Metaspace free after GC to avoid shrinking |
70 in range(0, 100) | 80 |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| MaxMetaspaceSize | size_t | Maximum size of Metaspaces (in bytes) | max_uintx | 512m |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| MaxNewSize | size_t | Maximum new generation size (in bytes), max_uintx means set ergonomically |
max_uintx in range(0, max_uintx) | 2g |
| 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) | 512m |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| MinMetaspaceExpansion | size_t | The minimum expansion of Metaspace (in bytes) | ScaleForWordSize(256*K) in range(0, max_uintx) | 4m |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| MinMetaspaceFreeRatio | int | The minimum percentage of Metaspace free after GC to avoid expansion |
40 in range(0, 99) | 50 |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| NewSize | size_t | Initial new generation size (in bytes) | ScaleForWordSize(1*M) | 2g |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| ParallelGCThreads | uint | Number of parallel threads parallel gc will use | 0 | 2 |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| StackShadowPages | int | Number of shadow zone (for overflow checking) pages of size 4KB. If pages are bigger shadow zone is aligned up. This should exceed the depth of the VM and native call stack. |
DEFAULT_STACK_SHADOW_PAGES | 20 |
| 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. |
gc*:file=/var/log/gc.log | |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| ms | <size> | set initial Java heap size | 4g | |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| mx | <size> | set maximum Java heap size | 4g | |
| Analysis | OK | |||
| Name | Type | Description | Default Value | Your Value |
|---|---|---|---|---|
| ss | <size> | set java thread stack size | 1m | |
| Analysis | OK | |||