What is JVM startup parameter: -XX:-TieredCompilation?

Usage:

This flag allows you to disables the use of tiered compilation.

Since:

Starting from JDK 6.

Examples:

This will instruct JVM to disable the use of tiered compilation:

java -XX:-TieredCompilation MainClass

Description:

This flag disables intermediate compilation of the execution level C1 so that a method is either interpreted or compiled at the maximum optimization level (C2). As a side effect TieredCompilation flag also changes the number of compiler threads, the compilation policy and the default code cache size. Note that with TieredCompilation disabled

• there will be less compiler threads;
• simple compilation policy (based on method invocation and backedge counters) will be chosen instead of advanced compilation policy;
• default reserved code cache size will be 5 times smaller.

Default Value:

By default, this option is enabled.

Errors:

An exception is thrown if the JVM doesn’t not support the flag.

Related Posts:

• Java Virtual Machine - Compilation Levels
• Java Oracle

NOTE:

Only the Java HotSpot Server VM supports this option.

The execution levels supported by the compilation system are:

• level 0 - interpreter
• level 1 - C1 with full optimization (no profiling)
• level 2 - C1 with invocation and backedge counters
• level 3 - C1 with full profiling (level 2 + MDO)
• level 4 - C2