[iOS] Interesting CPU activity

I’m trying out the iOS support in SDL (which is very cool!) and when I run this really simple program, I see regular repeated spikes in the CPU usage meter both inside Xcode and in Instruments.

Here’s the (very stripped down) source code I’m running:

And here’s a screen grab of what I’m seeing in Xcode:

I ran testgl2 from the Mac OS X tests, and didn’t see anything similar, so it’s either my code or it’s an iOS thing.