On Wed, Nov 27, 2013 at 7:35 PM, Vince Weaver <vi...@deater.net> wrote: > On Tue, 12 Nov 2013, Stephane Eranian wrote: > >> This patch adds a new uncore PMU to expose the Intel >> RAPL energy consumption counters. Up to 3 counters, >> each counting a particular RAPL event are exposed. >> >> The RAPL counters are available on Intel SandyBridge, >> IvyBridge, Haswell. The server skus add a 3rd counter. > > So I notice PP1 (which is the GPU power on non-server chips) > is not supported. > > Is that just for simplicity? > Does it work on specific models only? I bet so. How to detect those?
>> The following events are available and exposed in sysfs: >> - power/energy-cores: power consumption of all cores on socket >> - power/energy-pkg: power consumption of all cores + LLc cache >> - power/energy-dram: power consumption of DRAM (servers only) > > This "power" naming seems a bit generic. If other hardware has power > measurements can they be put in the same directory? > power/gpu? power/usb? > I think so. > Also, can support for reading the power from other vendors be put here? > Like AMDs (unfortunately named) APM (active power management) power > readings? > >> Files are: >> /sys/devices/power/events/energy-*.unit >> /sys/devices/power/events/energy-*.scale > > Are all of these sys files having documentation added under > Documentation/ABI? > Not yet. >> The RAPL PMU is uncore by nature and is implemented such >> that it only works in system-wide mode. Measuring only >> one CPU per socket is sufficient. The /sys/devices/power/cpumask >> file can be used by tools to figure out which CPUs to monitor >> by default. For instance, on a 2-socket system, 2 CPUs >> (one on each socket) will be shown. > > do the measurements require CAP_SYS_ADMIN like other system-wide uncore > measurements? It didn't look like it in the patch but I might have missed > it. > Measurements are limited to system-wide counting. Thus, you need CAP_SYS_ADMIN. > I'm sure the security people will start making claims that you can make > guesses about password encryption algorithms based on the global power > consumption numbers. > > > Sorry if these are annoying questions, I am glad to see this driver make > progress, as I've had the misfortune of maintaining various user-space-MSR > hacks designed to get this info because of lack of kernel support. > You don't really need a driver, you can also just use modprobe msr + the turbostat utility now part of the kernel source tree. It taps into the same counters. -- 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/