My workstation's CPU has been throttling and/or running slow for the past 48 hours. Here are the commands that I used to debug the problem.
First, core temperatues were checked:
$ watch sensors
coretemp-isa-0000
Adapter: ISA adapter
Physical id 0: +33.0°C (high = +80.0°C, crit = +100.0°C)
Core 0: +28.0°C (high = +80.0°C, crit = +100.0°C)
Core 1: +29.0°C (high = +80.0°C, crit = +100.0°C)
Core 2: +33.0°C (high = +80.0°C, crit = +100.0°C)
Core 3: +30.0°C (high = +80.0°C, crit = +100.0°C)
... but thes CPU are running at a reduced speed:
$ grep -E '^model name|^cpu MHz' /proc/cpuinfo
model name : Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
cpu MHz : 1700.156
model name : Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
cpu MHz : 1761.406
model name : Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
[..]
(this didn't work)
The solution I chose was to disable pstate driver altogher. I added kernel option intel_pstate=disable to /etc/default/grub, variable GRUB_CMDLINE_LINUX. Then, ran grub2-mkconfig, followed by a reboot.
CPU are not throttling, but do not boost. It is an adequate solution for now.
Here is another solution.
for G in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
echo -n performance > $G
cat $G
done
What I/O schedules is my system using?
% for x in /sys/block/*/queue/scheduler; do echo $x; cat $x; done
/sys/block/md127/queue/scheduler
none
/sys/block/sda/queue/scheduler
noop deadline [cfq]
[..]
I decided to change to deadline schedule with hope for less UI hangs: grubby --update-kernel=ALL --args="elevator=deadline"
-
General drive info:
sudo hdparm -I /dev/sdd -
SMART error log:
smartctl --all /dev/sdd
More info: https://www.cyberciti.biz/tips/linux-find-out-if-harddisk-failing.html
-
Trace IO processes: `sudo iotop -obtqqq | grep jbd2"
-
Why is Kworker taking 99.99%
sudo perf record -g -a sleep 10
sudo perf report