Linux App CPU Usage

I’ve had reports from a user of mine running Linux that my app is taking 50 to 60% CPU time while just sitting idle. Tonight I checked out my instance of my app running in Linux and sure enough running TOP in terminal in Ubuntu shows a cpu time of between 55 and 60% when the app is just sitting there.

I use Aaron Ballman’s (or is it Alex Restrepo’s - I forget) thread pool manager class in my app so there’s a constant loop in the thread that sleeps each loop iteration if there’s nothing being added to the thread pool. I know if the sleep value is too low that this can increase CPU time. So I experimented and raised it to 10 seconds. No difference. Now I’ve tried suspending the thread until a new item is added to the pool. No difference. I’m still seeing 56% CPU time. The only items running are the main thread and the thread pool thread which is suspended.

I do have a number of TCP sockets open but that shouldn’t affect CPU time.

What’s causing this? Is it just the way the framework handles things in Linux and it really doesn’t matter?

Thanks,

Jon