The JVM uses a cache of monitors, called the monitor cache. Each monitor is assigned to an object when locking of that object is required. However, contention for the Monitor Cache can become quite high in a busy program. Splitting the Monitor Cache into multiple caches reduces contention on the JVM locks controlling assignment of a monitor to an object. Suggested values are 16x128, 16x256, and 32x256.
N sets the thread local monitor parameters.
N, the number of thread local cache entries, is set to 8 by default. This option is available beginning with version 1.1.7. The montlscache option reduces contention for assigning a monitor to an object by creating a thread local cache of monitors. When set to the proper value, contention for the Monitor Cache lock is eliminated. Suggested alternative values are 16 and 32.