Visual Studio Profiler Team Blog : profiler

Using the keyboard to profile an application (Alt-F2 shortcut)

profiler — Tue, 29 Dec 2009 22:26:07 GMT

In announcing Visual Studio Beta 2 profiler features, Chris mentioned that we have a new option on the Debug menu called ‘Start Performance Analysis’ which has the Alt-F2 keyboard shortcut. This makes it easier than ever to start profiling your application. The new menu item has the following behavior:

You must have a Visual Studio Solution open in order to enable it.
If you have a solution open, but do not have a launchable current performance session, Start Performance Analysis launches the Performance Wizard.
If you have a solution open and have a launchable current performance session, Start Performance Analysis starts profiling.

Let’s use this new functionality to profile an application that I have prepared earlier.

Open the solution with ‘Alt-F, J, Enter’:
Start Performance Analysis with ‘Alt-F2’, which brings up the wizard:
Press ‘Enter’ to choose the default ‘CPU Sampling’ profiling method and move to the target selection page:
Press ‘Enter’ to select the only launchable project in the solution and move to final wizard page:
Press ‘Enter’ to finish the wizard and start profiling:
The report will open when profiling finishes:

If you wish to profile again, selecting Alt-F2 will start profiling with the Performance Session that was created after step #4.

[Colin Thomsen]

VS2010: Attaching the Profiler to a Managed Application

profiler — Mon, 07 Dec 2009 19:50:00 GMT

Before Visual Studio 2010, in order to attach the profiler to a managed application, certain environment variables had to be set using vsperfclrenv.cmd. An example profiling session might look like this:

vsperfclrenv /sampleon
[Start managed application from the same command window]
vsperfcmd /start:sample /output:myapp.vsp /attach:[pid]
[Close application]

If the environment variables were not correctly set, when attempting to attach you would see this message:

The profiling environment for ConsoleApplication2 is not set up correctly. Use vsperfclrenv.cmd to setup environment variables. Continue anyway?

The generated report would typically look something like the report below. The warning at the bottom of the page indicates the problem and the report itself would typically not be useful since no managed modules or functions would be resolved correctly.

Report with 'CLRStubOrUnknownAddress and Unknown Frame(s) and the warning ‘It appears that the file was collected without properly setting the environment variables with VSPerfCLREnv.cmd. Symbols for managed binaries may not resolve’.

Fortunately the Common Language Runtime (CLR) team provided us with a new capability to attach to an already running managed application without setting any environment variables. For more detailed information take a look at David Broman’s post.

Caveats:

We only support attach without environment variables for basic sampling. It will not work for Allocation or Object Lifetime data collection and Instrumentation attach is not possible. Concurrency (resource contention) attach is supported.
The new attach mechanism only works for CLR V4-based runtimes.
The new attach mechanism will work if your application has multiple runtimes (i.e. V2 and V4 SxS), but as noted above, you can only attach to the V4 runtime. I’ll write another post about the profiler and Side by Side (SxS).
The old environment-variable-based attach still works, so you can still use that if you prefer.

The new procedure for attaching the profiler to a managed application in Visual Studio 2010 goes like this:

Launch your app (if it isn’t already running)
Attach to it, either from the command-line or from the UI.
When you’re finished, detach or close the app to generate a report.

If you want to diagnose any issues with attach, the CLR V4 runtime provides diagnostic information via the Event Log (view with Event Viewer) and the profiler also displays information there:

Event Log: ‘Loading profiler. Running CLR: v4.0.21202. Using ‘Profile First’ strategy’

There are two .NET Runtime messages regarding the attach, the first indicating that an attach was requested and the second that the attach succeeded. The VSPERF message describes which CLR is being profiled.

[Colin Thomsen]

See The Profiler At PDC2008

profiler — Mon, 27 Oct 2008 10:39:00 GMT

Steve Carroll, development lead for the Visual Studio Profiler, will be at PDC2008 next week giving a presentation on the profiler:

What: TL24: Improving .NET Application Performance and Scalability
When: Wednesday, October 29th, 1:15pm - 2:30pm
Where: Room 153
Abstract: “Performance must be considered in each step of the development lifecycle. See how to integrate performance in design, development, testing, tuning, and production. Work with tools and technologies like: static analysis, managed memory profiling, data population, load testing, and performance reports. Learn best practices to avoid the performance pitfalls of poor CPU utilization, memory allocation bugs, and improper data sizing.”

If you’re going to be there, it’d be worth checking out some of the new features we’ve been working on as well as seeing how the profiler and load testing tools in Visual Studio Team System can help you improve your software.

UPDATE: The video of this session is now available online. It covers a bunch of new profiler features including Javascript profiling, contention profiling, 'hot lines' source code highlighting, summary page and other UI improvements, load-test integration and numerous other changes that will be shipping in Visual Studio 2010 (Team System).

[Chris Schmich & Colin Thomsen]

Walkthroughs: Using VSTS Test and Profilers to Find Performance Issues

profiler — Wed, 15 Oct 2008 23:54:00 GMT

Tess Ferrandez recently wrote a couple of articles that extend her popular series of debugging labs to focus on measuring and improving performance.

In 'Using VSTS Test and Profilers to troubleshoot performance issues (low cpu hang)', Tess introduces a performance problem into an ASP.NET application and uses the Visual Studio Profiler with a Load Test to track down the problem.
In 'Using VSTS Test and Profilers to troubleshoot a High CPU in GC issue', Tess tracks down a string concatenation issue that is causing high CPU usage due to garbage collection.

The walkthroughs include sample code, lots of screenshots and analysis.

[Colin Thomsen]

Tip: VS2008 – Finding and Setting Properties (Right-Click)

profiler — Mon, 22 Sep 2008 20:02:00 GMT

The Visual Studio Profiler has many properties and options and this tip shows you where to find most of them. Future posts may cover some of the specific properties in more detail.

Performance Session:

Select an existing Performance Session in the Performance Explorer to see properties in the Properties Window. If the Properties Window is hidden:
Press ‘F4’ or go to
‘View->Properties Window’.

Performance Report:

Select a Performance Report in the Performance Explorer to view many properties including Collection, ETW, General, Machine Information, Performance Counters, Process, Thread and Version Information.

Performance Session Properties (and Options):

To adjust Performance Session properties:

Right-click on the Performance Session (Performance1 in this example).
Select ‘Properties’.

Properties for Performance1 are shown below. There are different categories of properties on the left (e.g. General, Launch, Sampling, …).

Performance Targets:

To adjust Performance Target properties:

Right-click on the Target (ConsoleApplication3 in this example).
Select ‘Properties’.

Adjust the properties for the Performance Target as required. These properties do not often need to be changed, with the possible exception of the Instrumentation property ‘Exclude small functions from instrumentation’.

Tools –> Options –> Performance Tools:

Some global options can be configured using the Visual Studio Options dialog, which is accessed via:
Tools –> Options –> Performance Tools

That’s all the properties I can think of but I’m probably missing some still. Probably the most important aspect to this tip is to emphasize that right-clicking with the mouse is often the way to access important contextual information.

[Colin Thomsen]

Tip: VS2008 - Understanding Performance Targets

profiler — Fri, 18 Jul 2008 23:59:00 GMT

If you have a solution that contains multiple projects it is important to know what the 'Targets' group in the Performance Explorer is used for. The PeopleTrax solution shown on the right has 4 projects, with 3 of them compiling to managed DLLs and 1 compiling to an executable.

After running the Performance Wizard to create a Performance Session the Performance Explorer contains a single target as shown below.

Only the project that compiles to an executable is listed in the 'Targets' folder (for other project types like websites it would include the default launch project). What about the other 3 projects? As this tip explains, it depends upon the type of profiling you wish to do.

Sampling

With sampling there is no need to add the additional projects to your targets list. We do not modify assemblies when sampling and we will automatically attempt to collect data for any assemblies loaded by the PeopleTrax target. The only exception to this requirement is if you wish to collect data for multi-process scenarios and therefore need to launch multiple targets.

Instrumentation

For instrumentation, if you wish to collect data for the additional projects they should be added to your targets list as follows:

In the Performance Explorer, right-click on the 'Targets' folder:
Choose 'Add Target Project' to display a dialog:
Select the assemblies you wish to collect Instrumentation data for and choose OK.

The selected projects will now be modified (instrumented) when you start profiling. You can selectively disable instrumentation for certain projects by right-clicking on the target and unchecking the 'Instrument' option.

Instrumentation properties for a specific target.

[Colin Thomsen]

Quick Tip: VS2008 - Compare Reports Quickly

profiler — Wed, 02 Jul 2008 20:00:00 GMT

While investigating a performance problem you may need to collect many Performance Reports and compare them. You can use the Performance Explorer to quickly compare two reports by:

Selecting two reports.
Right-clicking and choosing 'Compare Performance Reports...'

The oldest report will be used for the 'Baseline' report and the other report will be used for the 'Comparison' report, as shown below:

[Colin Thomsen]

What code path is allocating the most bytes for a type?

profiler — Sun, 15 Jun 2008 02:26:00 GMT

In Visual Studio 2008, we added the ability to quickly determine the most expensive call stack in your application. In profiler parlance, the “most expensive call stack” is known as the “hot path”. What do we mean by “expensive”? “Expensive” is whatever measure you want it to be: number of samples in a function, time spent in a function, or even number of bytes or allocations in a function.

If you profile the managed memory usage of your application (also available in VS2008), you will get a new view in your profiling report called the Allocation View:

For each managed type allocated in your application, this view will show you the call stack where each allocation took place as well as the number of bytes and instances allocated in each function.

You can explore these call trees as you do normally, including using hot path to find the expensive allocation paths through your code for a specific type. This is accessible through either the toolbar or the context menu by right-clicking on the function from where you want to start hot path:

In this example, we know we’re allocating about 741KB of memory for System.Drawing.Graphics objects. Using hot path, we can quickly determine that the majority (67%) of the bytes are being allocated in System.Drawing.Graphics.FromHwndInternal. Because we do not control this code, we can look up the stack until we see code that we can change: MainForm.SetCell. This would be a great place to begin investigation.

It’s important to note that the allocation hot path is not the single function allocating the most bytes in your application (you can use the Function View for that). Instead, it is the specific path through your code that is allocating the most bytes for a type.

[Chris Schmich]

Very Quick Tip: Getting the most out of your screen for viewing call trees

profiler — Wed, 04 Jun 2008 21:58:00 GMT

I spend a lot of time in the profiler's Call Tree view when I use the profiler. When you are really digging deep into the tree, screen real estate becomes a big issue. There is one very simple Visual Studio trick that really helps out so you can get more of the call tree on the screen at one time without scrolling around. Set the focus on the call tree view and hit Shift-Alt-Enter. It will bring up a full screen view of just the document you are working on which makes it much easier to do the data analysis (especially on wide screen monitors). This works in all VS documents.

[Steve Carroll - scarroll]

Quick Tip: "Save Analyzed" for large VSP files

profiler — Sun, 18 May 2008 09:54:00 GMT

One cool new feature in the Visual Studio 2008 Profiler is the ability to take a large VSP file that has been analyzed once and save the report data into a VSPS file (Visual Studio Profiler Summary files). Saving the analyzed data has several major benefits:

The analyzed data is orders of magnitude smaller than the VSP file. We've seen 4GB trace VSPs get compressed into less than 100K VSPS files.
Because the data saved in the VSPS files has already been processed by our data analyzer, it will load up much faster.
Symbol data is automatically packed into the VSPS file.

VSPS files because of their small size, quick analysis, and saved symbols are perfect for use as saved baselines with the new performance comparison functionality in VS2008. A best practice is to regularly save off VSPS files for your performance scenarios so you can look for performance regressions from one milestone to the next.

This feature is not particularly discoverable. Here's a quick map of where to find it (highlighted in yellow):

One caveat: because the data has already been analyzed in the VSPS file, you can't use filters on VSPS files.

[Steve Carroll - scarroll]

Performance: Find Application Bottlenecks with Visual Studio Profiler

profiler — Wed, 23 Apr 2008 03:05:00 GMT

A couple of members of the profiler team recently wrote an article for msdn magazine, which describes how to use the Visual Studio 2008 profiler to improve the performance of an application. They examined a Mandelbrot fractal drawing program in some detail and isolated and fixed several performance problems in the code, speeding up program execution time approximately tenfold.

[colinth]

Articles on new Visual Studio Team System 2008 profiler features

profiler — Fri, 19 Oct 2007 20:10:00 GMT

I’ve recently been working on a series of post on my blog about many of the cool new features that we are adding in Visual Studio Team System 2008 (codename Orcas). So I figured that I’d post a quick link here to all the articles that I’ve finished so far.

Collecting Performance Counter information with the Visual Studio Profiler

Pinpoint a performance issue using hotpath in Visual Studio 2008

The Visual Studio Profiler Data Collection Control Part 1: Excluding Application Startup Time

Comparing performance reports with the Visual Studio Team System Profiler

[ianhu]

S. Somasegar on new profiler features

profiler — Wed, 19 Sep 2007 01:33:00 GMT

S. Somasegar the VP of Developer Division has just put up a post on his weblog detailing some new profiler and debugger features up coming in VS 2008. Check out the article here.

[ianhu]

Welcoming Colin to the profiler team

profiler — Sat, 12 May 2007 01:23:00 GMT

We recently added a new team member here in profiler land and he’s up and kicking with a blog already. Check out Colin’s blog here for his first entry on basic profiler scenarios.

~Ian

Introducing new Visual Studio Profiler Features in the Orcas Beta

profiler — Tue, 03 Apr 2007 22:32:00 GMT

Hey all, I'm rolling out a new series of articles about the new Visual Studio Team System Profiler features that will be included with the latest Orcas beta release. Check out the first article on comparison documents here.

~Ian