Comment 12 for bug 1018092

I found the magic sauce for getting the PMU event counters working in recent upstream code. On the 4460 the EMU clock has to be forced on. A patch for this, and for missing PMU/CTI interrupt mods is being applied to our 3.4 branch now. With this it will be possible to build a kernel with hardware event counters enabled and use perf to collect counter data. Bear in mind there is still nothing we can do to really work around the problem of occasional lost PMU interrupts, as that is a hardware issue.