> I suppose that's fair that it's better for some use cases. The flip > side is that it's no longer possible to get exactly accurate counts > from user space if you're using the PMI (because any events between > the overflow itself and the transition to the PMI handler are > permanently lost) which is catastrophically bad for us :)
Yes that's a fair point. For most usages it doesn't matter. I suspect that's a case for supporting opt-out for freezing per perf event, and rr using that. -Andi