Hello so using rdpmc() and the mmap page to do fast perf_event reads seems to interact poorly with the PERF_EVENT_IOC_RESET ioctl.
>From what I can tell, on reset event->count is set to zero, but event->hw.prev_count is not, so the userpg->offset field ends up negative and weird things happen. Shout reset just not be called if you are using the rdpmc() interface? Vince