(In reply to Ionuț Goldan [:igoldan], Performance Sheriff from comment #1)
This is a really tricky situation. Had 2 explanations for this so far, but none held.
It's possible this is some sort of performance intermittent regression.
My new explanation now: between May 29 and June 1 a Windows infra change happened. Now, why am I not able to reproduce this on older commits? It's possible the infra change problem kicks in because of a Bugzilla bug that's also related to Windows.
:aklotz could you look into this weird situation? I'm pretty much clueless at this point. The test outputs bimodal data at this moment, which is not ideal.
Unfortunately I don't really have any ideas as to what is going on. The good news is that, even though that alert shows a spike in startup I/O, it is not on the main thread. I'd be more concerned if the I/O was for the main thread, but since it isn't, and in the absence of any other corroborating evidence of negative impact, I'm inclined to say that we should just eat this regression.