Package: linux-image-6.1.0-9-amd64
Version: 6.1.27-1
Below, I try to cap the frequency for each of my processor cores, but some
cores resists:
# for i in `seq 0 7`; do echo "400000">
/sys/devices/system/cpu/cpu$i/cpufreq/scaling_max_freq && cat
/sys/devices/system/cpu/cpu$i/cpufreq/scaling_cur_freq; done 400002 400004
399989 2300000 2300000 2300000 400013 399519
Moreover, the cores that resist changes each time; e.g., the next run yields
this:
# for i in `seq 0 7`; do echo "400000">
/sys/devices/system/cpu/cpu$i/cpufreq/scaling_max_freq && cat
/sys/devices/system/cpu/cpu$i/cpufreq/scaling_cur_freq; done 400024 2300000
400002 400020 2300000 400000 399930 400008
I tried to read the frequency via /proc/cpuinfo:
# for i in `seq 0 7`; do echo "400000">
/sys/devices/system/cpu/cpu$i/cpufreq/scaling_max_freq; done && cat
/proc/cpuinfo | grep MHz cpu MHz : 400.001 cpu MHz : 399.989 cpu MHz : 2300.000
cpu MHz : 400.107 cpu MHz : 1028.210 cpu MHz : 399.942 cpu MHz : 400.001 cpu
MHz : 400.004
I also tried to use tlp (yes, I said TLP_DEFAULT_MODE=BAT,
TLP_PERSISTENT_DEFAULT=1, CPU_BOOST_ON_BAT=0, and CPU_HWP_DYN_BOOST_ON_BAT=0)
and sysfs packages; all methods yield the similar results: capping the
frequency of all cores doesn't work. I tried to cap all at, say, 800 MHz, 1.2
GHz, and 2 GHz instead, but the result is often (but not always!) the same: a
few cores often (but not always!) resist and run at higher frequencies up to
2.4 GHz. Only seldom I see the expected:
# for i in `seq 0 7`; do echo "400000">
/sys/devices/system/cpu/cpu$i/cpufreq/scaling_max_freq; done && cat
/proc/cpuinfo | grep MHz cpu MHz : 400.004 cpu MHz : 399.988 cpu MHz : 399.999
cpu MHz : 400.011 cpu MHz : 399.980 cpu MHz : 400.048 cpu MHz : 400.002 cpu MHz
: 400.008
But running cat /proc/cpuinfo | grep MHz a few seconds later yields again a few
lines with 2300.000.
The governor is powersave everywhere.
For kernel 5 with Debian 11 (which I can no longer test), everything worked
like a charm (or at least I always observed all-400-MHz back then). So either
the new kernel is erroneous or my processor broke somehow (perhaps, during the
upgrade). It has Intel(R) Core(TM) i7-10610U CPU @ 1.80GHz.
Who is the culprit? What to do?
Gratefully,
AlMa
