On Tue, Jan 12, 2016 at 10:00:18AM -0500, Matthew Gillen wrote: > Recent kernels (not sure exactly when this started) have been driving > me crazy. > For reference: Machine: Dell Precision with Intel Core i5 > OS: Fedora 23 (kernel 4.2.8-300.fc23.x86_64) > > When running on battery, everything is fine when using the default > "powersave" governor. Lately though, if I don't use the 180W power > supply that came with the computer (e.g. because I don't want that > beast in my travel bag), the kernel seems to be restricting CPU > speeds to something outside of what the governor claims to be > managing. > > Here's what I mean: > $cat /proc/cpuinfo > processor : 0 > vendor_id : GenuineIntel > cpu family : 6 > model : 60 > model name : Intel(R) Core(TM) i5-4340M CPU @ 2.90GHz > cpu MHz : 365.332 > ... > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver > intel_pstate > $cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor > powersave > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq > 3600000 > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq > 800000 > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq > 367257 >
The problem is in the intel_pstate governor. https://www.kernel.org/doc/Documentation/cpu-freq/intel-pstate.txt .... For contemporary Intel processors, the frequency is controlled by the processor itself and the P-states exposed to software are related to performance levels. The idea that frequency can be set to a single frequency is fiction for Intel Core processors. ..... -dsr- _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
