[+perf tool maintainers] On Thu, Aug 14, 2014 at 4:30 PM, Andi Kleen <a...@linux.intel.com> wrote: > > I understand all your points, but there's no alternative. > The only other way would be to disable INST_RETIRED.ALL. > You cannot do that either. INST_RETIRED:ALL is important. I assume the bug applies whether or not the event is used with a filter.
I think we need to ensure that by looking at the perf.data file, one can reconstruct the total number of inst_Retired:all occurrences for the run. With a fixed period, one would do num_samples * fixed_period. I know the Gooda tool does that. It is used to estimate the number of events captured vs. the number of events occurring. So what I am saying is that on BDW, we need to have perf force PERF_SAMPLE_PERIOD even with a fixed period is passed. The kernel cannot simply add PERF_SAMPLE_PERIOD to the event sample_format because the tool would get confused by the sample record size otherwise. I understand this is not pretty. We'd need to have a on the evsel just before making the syscall. That callback would be for x86 and it would check the CPUID to force PERF_SAMPLE_PERIOD. That's my thinking but there may be a better way of doing this. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
