From: Vitaliy Makkoveev <mvs@openbsd.org>
Subject: Re: Initial Raspberry Pi CPU frequency driver (apm -A)
To: Jan Stary <hans@stare.cz>
Cc: Ron Manosuthi <rman401@proton.me>, "tech@openbsd.org" <tech@openbsd.org>
Date: Sun, 11 Jan 2026 14:14:29 +0300

On Sun, Jan 11, 2026 at 11:30:17AM +0100, Jan Stary wrote:
> On Jan 11 10:53:31, mvs@openbsd.org wrote:
> > On Sun, Jan 11, 2026 at 09:45:56AM +0100, Jan Stary wrote:
> > > Hi Ron,
> > > 
> > > I am running this on my RPI4B -
> > > dmesg below, the difference being
> > > 
> > > 	-"firmware" at simplebus0 not configured
> > > 	+rpicpu0 at simplebus0: 600-1500 MHz
> > > 
> > > This is what sysctl hw says:
> > > 
> > > hw.machine=arm64
> > > hw.model=ARM Cortex-A72 r0p3
> > > hw.ncpu=4
> > > hw.byteorder=1234
> > > hw.pagesize=4096
> > > hw.disknames=sd0:a33e6029ac9d8f70
> > > hw.diskcount=1
> > > hw.sensors.bcmtmon0.temp0=53.07 degC
> > > hw.cpuspeed=1500
> > > hw.setperf=100
> > > hw.vendor=raspberrypi
> > > hw.product=Raspberry Pi 4 Model B Rev 1.4
> > > hw.serialno=10000000690ec9eb
> > > hw.uuid=31303030-3030-3030-3639-306563396500
> > > hw.physmem=8441495552
> > > hw.usermem=8441491456
> > > hw.ncpufound=4
> > > hw.allowpowerdown=1
> > > hw.perfpolicy=high
> > > hw.smt=0
> > > hw.ncpuonline=4
> > > hw.power=1
> > > hw.ucomnames=
> > > 
> > > So with hw.setperf=100 it runs at 1500.
> > > As a naive test, I recompiled the same kernel:
> > > 
> > > before:	34m45.95s real   108m28.41s user    19m37.55s system
> > > after:	19m25.87s real    59m24.15s user    10m21.18s system
> > >
> > 
> > Do you use 'passive' cooling? I mean without any fan. I'm curious about
> > temperature.
> 
> No cooling. I log the temperature on this machine every minute;
> here is the log from around when I was compiling this morning
> (alreayd running on the new rpicpu kernel):

Thanks. Without this diff on my RPI4 temperature does not exceed 51
degree. Will try this diff later. 

> 
> 202601110900 53.07
> 202601110901 53.07
> 202601110902 53.56
> 202601110903 53.07
> 202601110904 54.04
> 202601110905 54.53
> 202601110906 53.07
> 202601110907 52.58
> 202601110908 52.58
> 202601110909 54.04
> 202601110910 52.58
> 202601110911 53.07
> 202601110912 53.07
> 202601110913 53.56
> 202601110914 54.04
> 202601110915 52.58
> 202601110916 53.07
> 202601110917 54.04
> 202601110918 53.07
> 202601110919 61.84
> 202601110920 65.73
> 202601110921 65.73
> 202601110922 61.35
> 202601110923 65.73
> 202601110924 67.19
> 202601110925 68.17
> 202601110926 68.17
> 202601110927 69.63
> 202601110928 69.14
> 202601110929 71.09
> 202601110930 69.63
> 202601110931 71.58
> 202601110932 70.60
> 202601110933 71.58
> 202601110934 71.09
> 202601110935 72.06
> 202601110936 72.06
> 202601110937 65.73
> 202601110938 58.43
> 202601110939 55.99
> 202601110940 55.02
> 202601110941 52.58
> 202601110942 52.58
> 202601110943 51.12
> 202601110944 51.61
> 202601110945 50.63
> 202601110946 51.12
> 202601110947 50.15
> 202601110948 49.17
> 202601110949 49.17
> 202601110950 49.66
> 202601110951 48.69
> 202601110952 48.20
> 202601110953 47.71
> 202601110954 48.69
> 202601110955 47.71
> 202601110956 48.20
> 202601110957 48.20
> 202601110958 48.69
> 202601110959 47.23
> 202601111000 48.20
> 
> Below is a more detailed log from another such compilation (now)
> logging hw.sensors.bcmtmon0.temp0 every five seconds, starting
> just before make -j4 and ending after it starts cooling down.
> (To be clear, this is with apm -A).
> 
> 	Jan
> 
> 
> 48.20
> 48.69
> 53.07
> 55.02
> 54.53
> 55.99
> 55.50
> 57.45
> 58.43
> 57.45
> 58.43
> 59.40
> 59.40
> 60.86
> 60.86
> 61.84
> 60.86
> 60.37
> 62.81
> 61.35
> 61.35
> 62.81
> 62.81
> 62.32
> 63.30
> 61.84
> 62.32
> 62.81
> 63.78
> 64.27
> 63.30
> 62.81
> 64.27
> 63.78
> 64.76
> 64.27
> 63.78
> 64.76
> 64.27
> 64.27
> 64.27
> 65.73
> 65.24
> 64.76
> 66.70
> 66.22
> 65.73
> 66.70
> 67.19
> 65.73
> 66.70
> 67.19
> 67.19
> 66.70
> 67.19
> 67.19
> 67.19
> 67.68
> 66.70
> 67.19
> 67.68
> 66.70
> 67.19
> 67.68
> 68.17
> 68.17
> 67.19
> 67.19
> 67.19
> 68.17
> 68.17
> 69.14
> 68.17
> 68.17
> 68.17
> 69.63
> 68.17
> 68.65
> 68.65
> 69.14
> 68.17
> 68.17
> 68.17
> 69.63
> 68.65
> 69.14
> 70.60
> 69.63
> 70.11
> 69.63
> 69.14
> 70.60
> 71.09
> 70.60
> 69.14
> 70.11
> 70.11
> 70.11
> 69.14
> 70.11
> 70.11
> 69.63
> 70.11
> 70.11
> 70.11
> 70.11
> 71.09
> 70.11
> 70.60
> 70.60
> 70.60
> 70.11
> 70.11
> 69.63
> 70.11
> 70.11
> 71.58
> 71.09
> 70.60
> 71.58
> 71.09
> 70.11
> 70.60
> 70.60
> 69.63
> 70.11
> 71.58
> 70.60
> 71.58
> 71.09
> 71.09
> 71.58
> 72.06
> 72.06
> 71.58
> 72.06
> 71.09
> 72.55
> 72.06
> 72.55
> 71.58
> 71.58
> 72.06
> 72.55
> 71.58
> 71.58
> 71.58
> 71.09
> 73.04
> 72.55
> 72.06
> 72.06
> 72.06
> 73.52
> 72.06
> 71.58
> 71.09
> 71.58
> 72.06
> 72.06
> 71.09
> 72.06
> 71.58
> 73.04
> 72.06
> 71.58
> 71.58
> 72.06
> 71.09
> 72.06
> 71.58
> 72.06
> 72.55
> 71.09
> 71.58
> 71.58
> 72.55
> 72.06
> 72.06
> 71.09
> 70.60
> 72.55
> 72.06
> 72.55
> 71.58
> 71.09
> 71.58
> 72.55
> 72.06
> 70.60
> 71.58
> 72.06
> 71.58
> 71.58
> 71.09
> 72.55
> 72.55
> 72.06
> 71.09
> 71.09
> 71.58
> 72.06
> 72.55
> 72.06
> 72.06
> 72.06
> 72.06
> 71.58
> 72.55
> 69.63
> 66.70
> 66.70
> 65.24
> 67.19
> 66.70
> 67.19
> 66.22
> 65.24
> 62.81
> 62.81
> 62.32
> 62.81
> 61.84
> 60.86
> 60.86
> 59.89
> 59.40
> 58.43
> 58.43
> 58.43
> 58.43
> 58.43
> 56.97
> 56.97
> 56.97
> 57.45
> 55.99
> 55.99
> 56.97
> 56.48
> 55.99
> 55.99
> 55.50
> 55.99
> 55.50
> 55.99
> 55.50
> 56.97
> 55.02
> 55.50
> 55.02
> 55.02
> 53.07
> 54.53
> 54.04
> 54.04
> 54.04
> 53.07
>