iphone app performance data

Question

i was trying running application with instrument tool. but it collects so many data. so i am confuse where to look exactly in order to optimize my app. is there any best start up guide or any best practice. hope my question is genuine and clear.

Edit: attaching sample image from instrument.how to interpret this data. alt text http://www.freeimagehosting.net/uploads/7c99370ca9.png

click here for full screen Here

Answer 1

What that screenshot is showing me is that you have some leaks in your code. You can find out more details about them by turning on the extended detail. You can do this by going to View->Extended Detail you can then use this information to help you get rid of the leak.

If you want to look at the CPU performance of your app you can use the CPU Sampler that is built in to Instruments. You can access it from Xcode Run -> Run with Performance Tool -> CPU Sampler

Answer 2

In the leaks bar you see the orange spikes which show you the occurrence of the leak (the point in time it happened); the blue below it is an indication of the total leak amount which builds over time - you see it continue at one level for a while after the first leak, then you have the second leak and the total leaks display grows.

To get more detail double-click on the items in the list view. You will drill down to more levels of details and hopefully come to a view which will help you find the leak. But it's nowhere near as easy to see what is wrong as the little blue arrows that you get with a static analysis build...

The best approach I think is to make sure you are running Snow Leopard, the latest Xcode and start using static analysis. Since I started using it I found leaks in older code that Instruments hadn't revealed (probably my fault in not using it correctly, but anyway...) and I have found no new leaks in new code. The worst thing about it is false positives but it certainly kills leaks.