Use performance rules to analyze data
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
The performance warnings of Visual Studio Profiling Tools indicate issues in a profiled application that can slow program execution. Warnings can also indicate that you might need to change collection methods to collect more useful data. Performance warnings are generated automatically in a profiling session. Warnings appear in the Error List window when a profiling data file is opened in Visual Studio. From the Error List window, you can locate the source code of the issue, and you can display detailed information about the error, such as information about how to resolve the problem. You can also disable warnings in which you are not interested.
Note
Profiler performance warnings are generated by the dynamic analysis of program execution and are independent of Code Analysis warnings. Code Analysis can also generate performance warnings for managed code based on the static analysis of the source code. For more information, see Analyze managed code quality and Performance warnings.
In this section
Provides information about how to open the Error List window to view profiler performance warnings.
Provides information about how to turn individual performance warnings on or off.
Provides detailed information about the profiler performance warnings