Measuring device drivers CPU/IO utilization caused by my program

1
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Sometimes code can utilize device drivers up to the point where the system is unresponsive.

Lately I've optimized a WIN32/VC++ code which made the system almost unresponsive. The CPU usage, however, was very low. The reason was 1000's of creations and destruction of GDI objects (pens, brushes, etc.). Once I refactored the code to create all objects only once - the system became responsive again.

This leads me to the question: Is there a way to measure CPU/IO usage of device drivers (GPU/disk/etc) for a given program / function / line of code?

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c++windowsdebuggingdevice-drivermeasurement
If you want to see your program's effect as a whole, open up process explorer and look at threads under the system process, and under csrss.exe. Not sure if it's possible to correlate that to line/method etc though. – Billy ONeal
Take a look at this method. Its measurements are very rough, but it tells you exactly, down to the line of code, what's taking the time, and whether it's I/O or CPU. – Mike Dunlavey

3 Answers

3
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You can use various tools from SysInternals Utilities (now a Microsoft product, see http://technet.microsoft.com/en-us/sysinternals/bb545027) to give a basic idea before jumping in. In your case process explorer (procexp) and process monitor (procmon) performs a decent job. They can be used to get you a basic idea about what type of slowness it is before doing profiling drill down.

Then you can use xperf http://msdn.microsoft.com/en-us/performance/default to drill down. With correct setup, this tool can bring you to the exact function that causes slowness without injecting profiling code into your existing program. There's already a PDC video talking about how to use it http://www.microsoftpdc.com/2009/CL16 and I highly recommend this tool. Per my own experience, it's always better to observe using procexp/procmon first, then targeting your suspects with xperf, because xperf can generate overwhelming load of information if not filtered in a smart way.

In certain hard cases that involving locking contentions, Debugging Tools for Windows (windbg) will be very handy, and there are dedicated books talking about its usage. These books typically talk about hang detection and there are quite a few techniques here can be used to detect slowness, too. (e.g. !runaway)

2
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Maybe you could use ETW for this? Not so sure it will help you see what line causes what, but it should give you a good overall picture of how your app is doing.

0
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To find the CPU/memory/disk usage of the program in real time, you can use the resource monitor and task manager programs that come with windows. You can find the amount of time that a block of code takes relative to the other blocks of code by printing out the systime. Remember not to do too much monitoring at once, because that can throw off your calculations.

If you know how much CPU time that the program takes and what percentage of time the block of code takes, then you can estimate approximately how much CPU time that a block of code takes.