On 24/08/2017 00:29, R0b0t1 wrote: > As an example, I am interested in characterizing the power consumption > of rendering a PDF document. I would hopefully only need to run the > renderer once. > > I can use PowerTOP, but it seems to be limited to rough measurements > on the order of tenths of a watt. This measurement can be divided > among the wakeup events in an attempt to calculate software power > consumption but it seems imperfect if I want to monitor a single > process that may be competing relatively equally for resources with > the kernel and other user processes. > > PMBus is a spinoff of SMBus which is a spinoff of I2C which is found > on many motherboards. PMBus is supposed to be the interface which > controls and reports power supply activity. Besides the main kW power > supply, there is usually a power supply near your processor that steps > down 3.3V or 5V to 2.8V, 1.8V, or lower (I've seen as low as 0.8V, but > not on a desktop). I was not aware these had a visible interface. > > Apparently you can talk to these, but my searches can only find code > which seems highly experimental. The other replies seem to be for > embedded Linux systems running on FPGAs and perhaps Cortex-A parts. > > If I were using a microcontroller I could get uA or nA draw per MHz > and I know my operating voltage and operating time. However, desktop > processors are much more complex, and I am not sure if they have been > entirely characterized. The most advanced tool I can find is PowerTOP > and it does not seem very accurate. > > Does anyone have any suggestions? Should I start reading source code > or post on the forums?
Both of these sound good > Or perhaps someone has used PowerTOP and found > it to be reasonably accurate? No not this. PowerTOP was designed to find badly-behaving programs like pidgin that woke up and polled it's queue every 1ms or so. It's not for what you want at all, not even close. > > R0b0t1. > -- Alan McKinnon alan.mckin...@gmail.com
