Configures the number of additional mutexes to allocate. If an application will allocate mutexes for its own use, this parameter is used to add a number of mutexes to the default allocation.
         The syntax of this parameter in the DB_CONFIG file is a single
         line with the string mutex_set_increment, one
         or more whitespace characters, and the number of additional
         mutexes. Because the DB_CONFIG file is read when the database
         environment is opened, it will silently overrule configuration
         done before that time.
    
For more information, see DbEnv::mutex_set_increment().