On Tue, Apr 28, 2015 at 3:29 PM, Brown, Len <len.br...@intel.com> wrote: >> I think that turbostat could do some of its work without being >> root if we had a driver like this. > > Note that turbostat can be run as non-root this way: > > # setcap cap_sys_rawio=ep ./turbostat > # chmod +r /dev/cpu/*/msr > > For the debug case, there are a number of MSRs that turbostat must access, > so would still need permission for that case (which is the only case I use:-) >
True. This would only get the average turbo ratio. Of course, I think that can be done using cpu-cycles as well. >> Thoughts? Would it make sense at all? Did I wire it up right? This is >> the only PMU driver I've ever written, and it could have any number of >> issues. > > APERF/MPERF, as with all per-thread MSRs, must be accessed > from the local processor. I didn't see where this driver > distinguishes the CPU. Also, I assume the intent is to return > a snapshot, rather than sampling, yes? I think that the perf core takes care of that for us, but I'm not entirely sure. --Andy -- 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/
