During extreme heat, your AC running constantly is normal and actually more efficient than cycling on and off. As long as your unit is properly sized and reaches its set temperature, you don't need to worry.
Chapters
You don't want to stop running. I mean, think about when it's 98, 100 degrees outside. Think about getting in your car and then driving to the store. How many times did you turn off the ac? Probably not ever. Your home's the same way. It's trying to keep that same temperature all throughout the day. So it's not going to stop running if it's on a set point it's trying to reach. Now, if it reaches that set point, then obviously it's going to turn off. But the unit running for a long period of time is not necessarily a bad thing if the unit is sized. To go back to the first question, if it's sized properly, it is running. It is better for it to run longer because it's more efficient than turning on, turning off, turning on, turning.