Re: baseline power consumtion kernel > 5.3.10

["Rafael J. Wysocki" <rafael@kernel.org>]

On Thu, Dec 5, 2019 at 8:52 AM Guido Riedel <guido.riedel@web.de> wrote:
>
> Hi,
>
> Since Kernel 5.3.11 I got a significant increased baseline Power
> consumption. I tried up to 5.4.1 on arch linux. Powertop shows an
> increase from 3.6W on 5.3.10 to 5.x W on higher Kernels. My laptop fan
> spins a lot more.
>
> I read that a lot of Intel stuff has entered the Kernel in 5.3.11, could
> this cause it? Will it stay like this in the next Versions? Can I maybe
> switch something off etc. to get a lower baseline power?

That's possible.

It would be good to compare the general activity of the system
depending on which version of the kernel is in use.

The turbostat utility can be used for that.

It is included in the kernel source tree (tools/power/x86/turbostat/).
Build it, install it (the version from 5.4.1 can be used with older
kernels too), run it along with your normal workload for some time
with both 5.3.11 and 5.4.1, like this:

# turbostat --quiet --out=output_file sleep 600

(this will cause it to run until the "sleep 600" command is complete,
i.e. for 10 minutes).  Then post the output files from both runs.

Note that you need to run it as root (there is a man page etc).

Thanks!