Re: Off-topic therml_stats - trans_table - File too large (exceeding static page alloc)

[Thomas Renninger <trenn@suse.de>]

Am Mittwoch, 11. November 2020, 11:30:18 CET schrieb Viresh Kumar:
> On 11-11-20, 09:42, Thomas Renninger wrote:
> > Hi,
> > 
> > sorry for high-jacking this thread, it is at least related and afaik you
> > are deeper involved in this:
..
> > and when it seem to get interesting (device 4 and 5), I get:
> How many total states are there ? Must be really large.
..

Ah, yes. The first 4 devices which have 3 thermal states seem to be connected to each CPU
via ACPI:
/sys/devices/virtual/thermal/cooling_device0/device -> ../../../LNXSYSTM:00/LNXCPU:00

The latter two, device 4+5 do not have this "device" sysfs link at all and cooling_device4 has 50,
cooling_device5 20 states.

All cooling devices max_state:
cat /sys/devices/virtual/thermal/cooling_device*/max_state 
3
3
3
3
50
20

cur_state is 0 by default for all.
Doing something like (not sure it was a 2):
echo 2 >/sys/devices/virtual/thermal/cooling_device4/cur_state
ends up in:
Nov 11 23:33:27 c100 kernel: NOHZ: local_softirq_pending 80
Nov 11 23:33:27 c100 kernel: NOHZ: local_softirq_pending 80
Nov 11 23:33:21 c100 kernel: intel_powerclamp: Start idle injection to reduce power
in kernel logs.

But echoing this static cur_state number in, seem to trigger dynamic adjusting
and the number gets up and down by itself:

while true;do cat /sys/devices/virtual/thermal/cooling_device4/cur_state;sleep 1;done
86
83
89
90
90
92
91
^C
c100:/home/trenn # cat /sys/devices/virtual/thermal/cooling_device4/max_state
50

Disabling works with setting cur_state to 0, but cur_state is -1 afterwards ?!?:
echo 0 >/sys/devices/virtual/thermal/cooling_device4/cur_state
cat /sys/devices/virtual/thermal/cooling_device4/cur_state 
-1

echo 1 >/sys/devices/virtual/thermal/cooling_device4/cur_state
c100:/home/trenn # cat /sys/devices/virtual/thermal/cooling_device4/cur_state 
86

It looks like any number echoed into the cur_state device, even above max_state enables
dynamic power adjusting:
echo 10100000 >/sys/devices/virtual/thermal/cooling_device4/cur_state
-> no error.

ACPI related CPU cooling devices 0-3 work as one would expect:
3 states (max_state) one can set them and trying to write something into cur_state
which is above max_state ends up in:
echo 4 >/sys/devices/virtual/thermal/cooling_device2/cur_state
bash: echo: Schreibfehler: Invalid argument.

Hardware:
Dell, Latitude E7470
cpu family      : 6
model           : 78
model name      : Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
stepping        : 3
microcode       : 0xd6


Adding Jacob who seem to be involved into powerclamp driver.
Maybe he can shed some light on this...

Thanks,

    Thomas