When profiling an application, which generates large number of events ~10000000, opening the profoling view takes a really long time, several seconds.

Most of that time is taken by one function: TimelineModelPrivate::incrementStartIndices.

Whenever a new event gets added into the timeline and it doesn't get added to the last index, that function gets called and it loops trough all previously added events even though it most like doesn't need to.