scarroll's Blog

One of our big missions here in VS Profiler land is to bring profiling tools to people who maybe haven't had access to one before. I know before I started here, I never really needed to use the Microsoft Symbol Server. However, for the profiler in sampling...

There was a problem with the original publication of the CLR Symbols for some binaries (mscoree, mscorwks, maybe others). This was causing the profiler to be unable to load symbols for these binaries. The end result was a lot of [mscoree.dll] function...

I had to help a high school kid solve this problem yesterday. It’s pretty interesting I think. I sent it around the team and people seemed to enjoy it so here you go. (In the old days, I would have saved this puzzle for an interview question, but pure...

VSinstr has two different categories of switches. The first category of switches control which methods get instrumented. The second category of switches control whether or not profiling collection is enabled or not. They are completely orthogonal. ...

A lot of my graduate work was in the area of parallel computing so we spent a lot of time with Amdahl's law. Amdahl's law states that if you can speed up some fraction F of the program by some speedup S, the overall speedup of the program is: 1 / ...

In the code coverage analysis in VSTS, we provide two types of stats: block coverage and line coverage. I just wanted to clarify a few points. First, when we say block coverage, we are referring to basic blocks in the binary being tested, *not* in...

The symbols for several key CLR Beta2 Symbols are finally on the symbol server. Go forth and profile! If you had previously sampled some managed apps and were disappointed with the stacks, please give it another try. Unfortunately, the DLLs that had...

This post is adapted from an internal mail. The customers were somewhat confused about the reason their callstacks looked so different in Sampling mode and Instrumentation mode. Let's say your program consists of only 2 DLLs, foo.dll and bar.dll. Foo...

I'm speaking at the Microsoft Meltdown 2005 conference at the end of the month. The topic is tips and tricks for using the Visual Studio Profiler. Since this is a game developer audience, I'm going to try to tailor this talk to your needs and go in to...

Total tangent here, but I just made a really great meal and I must blog about it. Side Dish: Roasted Grape Tomatoes Directions: 1) Grab a pint or so of grape tomatoes. They have them at Costco out here, but I've seen them in supermarkets. In a pinch...

Hey folks. We have a public chat scheduled for tomorrow. I just checked the schedule and we have a bunch of the devs, testers, PMs, who are responsible for the dev and test skus of Team System signed up to be on for tomorrow's chat. If you've never tried...

Sorry folks. I want to update this blog about this issue. We just made another symbol publication attempt to the symbol server of the CLR Symbols. We hope this one will go through. Just to sum up: The symbols distributed with the sdk for mscorwks, mscorlib...

I took the MSFT "Intern Mentoring" training last week in preparation for the impending arrival of my very first intern. It was about 2 hours of concentrated goodness. An Intern Mentor here at MSFT is the person who "manages" an intern. We're in charge...

What's the name of the paper? Efficient and Precise Dynamic Impact Analysis Using Execute-After Sequences [PDF] Who wrote it? Taweesup Apiwattanapong, Alessandro Orso, and Mary Jean Harrold at Geogia Tech. Background: Impact Analysis is...

The most common question that comes in to the internal profiler by far is "Why am I not seeing any managed code in my profiles?" Most of the internals who use our profiler like to do profile collection using the command line tools. The reason why this...

My illustrious co-worker, Ian, is compiling a central resource of all the most essential profiler blog posts .

The Code Coverage instrumentation in Visual Studio is based on binary instrumentation instead of source instrumentation. The binary built from your code is cracked open and probes are inserted in the basic block so we can track whether each block has...

Don't laugh! I've seen this happen a few times now. In the UI , if you are debugging your debug build and then switch to performance tools and push launch, you will be profiling your Debug bits! Don't do this. Make sure you have set your configuration...

So I'm going to try to add a new category of posts to this blog for interesting papers in Computer Science related conferences and journals. One thing that kind of blows my mind about CS lately is that even though we are more "connected" than we have...

This is actually just a corollary of the "Why don't instrumentation and sampling calltrees look the same" FAQ. In instrumentation, you will see all of the functions inside of the instrumented DLL as you would expect. However you will also see every...

Hey folks, I'm taking a quick survey. If you are currently using code coverage metrics in your project, which kind of metrics are you using and as a bonus, how do you decide what percentage is acceptable and are you satisfied with the metric? By coverage...

Here's another fun one from the internal support alias. When you profile with the VS Profiler, you are profiling the Release version of your code (I hope!). As you know from having debugged Release code in the past, sometimes things get a little funky...

The most common reason for this to occur in Instrumentation mode is that the dll you instrumented is appearing in two different processes. We don't aggregate data from multiple processes. You can see this easily by using vsperfreport.exe -summary:function...

I'm about 250 pages into The Art of Computer Systems Performance Analysis : Techniques for Experimental Design, Measurement, Simulation, and Modeling by R.K. Jain. I can recommend this book based on that 250 pages alone. It's a great course on how to...

I'll be on vacation for the next two weeks. I promise to be a good little blogger and write more posts about the profiler when I return. If you happen to be in Italy and see a hopeless looking Yank muttering in pidgin Italian trying to order gelato, that...