Set smoker to 225 degrees F
Trim excess fat that is over 1/4 inch thick, you can also score the top in a crosshatch pattern
Coat the loin with olive oil
Apply rub evenly over the entire loin
Place the pork loin directly on the grill grates and smoke for 30 to 45 minutes
Now place the loin in a pan on the smoker and leave uncovered for 30 to 45 minutes
Tent the loin with aluminum foil for 2 to 2 1/2 hours, this will help keep it moist
In the last 30 minutes, increase temperature on smoker to 250 degrees F
Cook until internal temperature reaches 145 degrees F
Remove from smoker and let rest still covered for 10 to 15 minutes
Slice against the grain and serve