I tend to launch most programs on my Windows 10 laptop by typing the <Win> key, then a few letters of the program name, and then hitting enter. On my powerful laptop (SSD and 32 GB of RAM) this process usually takes as long as it takes me to type these characters, just a fraction of a second.
Sometimes, however, it takes longer. A lot longer. As in, tens of seconds. The slowdowns are unpredictable but recently I was able to record an Event Tracing for Windows (ETW) trace of one of these delays. With a bit of help from people on twitter I was able to analyze the trace and understand why it took about a minute to launch notepad.
I loved reading every bit of this post. Even for someone not versed in programming, it’s quite easy to follow along and understand what is happening deep in the bowels of Windows when this bug occurs. I’ll spoil the surprise:
This deserves reiterating. My start menu was hung due to the combination of heap corruption and WerFault.exe deciding that it needed to upload the crash dump before releasing the old process so that a new one could be started.
And uploading the crash dump ran into issues, causing the delay. The tools to watch for bugs is causing more bugs. Who watches the watchers?