mysqlslap: Could not create thread

While using mysqlslap I am getting this error when I use -u root -p –create-schema=test --query="SELECT * FROM users" --concurrency=383 --iterations=1

My max connections in my.cnf is a lot higher than this 383, is there another setting I need to change or something in a different file that will allow me to have more connections. Anything 381 and lower works fine and 382 gives me the error mysqlslap: mysql_init() failed ERROR :