#Visual studio 2015 intellisense slow update

GC.Collect(2, GCCollectionMode.Optimized) Д«asically, Roslyn is putting the GC in the SustainedLowLatency mode whenever you type a character/cut/paste modify the current document, and restore the normal GC mode after 5 seconds and perform this optimized collect. I was wondering why the hell the GC is triggered even if I don't see to modify heavily the memory (even if Roslyn can be memory consuming, come on.), so I looked at the Roslyn repo to find out any explicit GC handling and found this code in GCManager:Д®very 5 seconds you stop typing into a file, this code is triggered: // hint to the GC that if it postponed a gen 2 collection, now might be a good time to do it.

Also when you look more closely at the diagram, it is occupying a full core for more than 20+ seconds. You can see on the diagram that the GC is blocked in a gc_heap/gc1 phase, while there is no particular reason for that.

Here is a screenshot of the xperf report: Then I tried to disable almost all extensions, but still while typing into a C# file, sometimes VS could get stuck for more than 10+ seconds!Дigging a bit more into this problem with xperf (with the shiny new WPR and WPA tools from Windows 10 SDK!) I discovered that it was mainly due to the GC (and maybe Roslyn) burning the CPU and the memory (If you are a C++ programmer, you can laugh at it, for sure). I first thought that it was ReSharper crawling VS. You can remove the registry key patch that was most likely unrelated!ДЄt work, we have switched to VS2015 and have been experiencing so far lots of 'Visual Studio Not Responding' while editing the code. It actually confirms that the issue was related to this bug in the GC. 3:02 AM and it seems to fix the issue detailed in this post!

#Visual studio 2015 intellisense slow update

Update 10 October 2015: I just tried the Hotfix KBs mentioned in the comment from Lee Coward