Visual Studio External Code High Self CPU Times

Question

I am working on a very large project in VS 2017. I am new to VS and it's debugging tools and am having a hard time understanding how to interpret the below call tree. From what I understand the self CPU time is the time taken by the calling method and the rest of the time is taken by the methods called within it. I am not sure why the first item in the tree is taking so much self CPU time. I ended up installing additional symbols to be able to interpret the external code and most of what I saw was starting/stopping threads and other low level operations (which I am not familiar with and doubt I can improve performance on). Why might my external code be running through so much self CPU time? Is there anything I can do to improve its performance? And are there any other methods/tools that could help elucidate what's going on here?

High Self CPU time for External Code

Answer 1

System and framework functions that are executed by your code are called external code. External code functions start and stop the app, draw the UI, control threading, and provide other low-level services to the app.

In most cases, the cpu time of the external code is fixed. So less cpu time of your managed codes means that lower the percentage of managed codes and the higher the percentage of external code.