I am porting an application to Ivy Bridge architectures using UNHALTED_REFERENCE_CYCLES. This counter works well on Sandy Bridge, but returns 0 on Ivy Bridge. I tried the provided ./example/syst_count example and the counter returns 0 as well. I am running the libpfm-4.3.0, Linux Debian Squeeze kernel 3.2.0, and I have attached a copy of my /proc/cpuinfo.
I believe Likwid 3.0 does support this counter (named CPU_CLOCK_UNHALTED_REF_P:PMC1).
Thank you for your time,