RPi and powerd, was: Re: RPI4 clock speeds and serial port ( temperatures idle and -j4 buildworld buildkernel )

Fri Mar 26 01:19:06 UTC 2021

[Eliminating bad history and replacing with test
information from corrected context, just -j6 for
now.]

On 2021-Mar-25, at 10:59, Mark Millard <marklmi at yahoo.com> wrote:

> [Turns out I somehow ended up with /etc/rc.conf not edited
> to enable powerd : that is what I found when I went back
> to disable it. Now I get to re-run the tests.]
> 
> On 2021-Mar-25, at 10:23, Mark Millard <marklmi at yahoo.com> wrote:
> 
>> On 2021-Mar-24, at 14:13, Mark Millard <marklmi at yahoo.com> wrote:
>> 
>>> On 2021-Mar-23, at 16:15, Mark Millard <marklmi at yahoo.com> wrote:
>>> 
>>>> On 2021-Mar-23, at 12:57, Mark Millard <marklmi at yahoo.com> wrote:
>>>>> 
>>>>> 
>>>>> On 2021-Mar-23, at 06:56, tech-lists <tech-lists at zyxst.net> wrote:
>>>>> 
>>>>>> Hi,
>>>>>> 
>>>>>> latest build run:
>>>>> 
>>>>> Had a -mcpu=cortext-a72 world and kernel been
>>>>> installed and booted first? Was the system
>>>>> running a world and kernel that had not been
>>>>> tuned for the Cortex-A72?
>>>> 
>>>> I've started an experimental build in my
>>>> -mcpu=cortex-a72 tuned context . . .
>>>> 
>>>>>>>>> World built in 22976 seconds, ncpu: 4, make -j6
>>>>>> --------------------------------------------------------------
>>>>>> 
>>>>>> 6 Hours : 22 Minutes : 56 Seconds
>>>>>> 
>>>>>> created kernel.bin from kernel.full
>>>>>> --------------------------------------------------------------
>>>>>>>>> Kernel build for GENERIC-NODEBUG completed on Mon Mar 22 13:54:53
>>>>>>>>> UTC 2021
>>>>>> --------------------------------------------------------------
>>>>>>>>> Kernel(s)  GENERIC-NODEBUG built in 2086 seconds, ncpu: 4, make -j6
>>>>>> --------------------------------------------------------------
>>>>>> 
>>>>>> 0 Hours : 34 Minutes : 46 Seconds

Based on the later results reported, I get a build that
takes a little less time for buildworld+buildkernel, a
build that does not involve devel/ccache .

So it could be that devel/cache had an empty cache for
your build for all I can tell from the timing information.

>>>>>> commands used:
>>>>>> 1. cd /usr/src
>>>>>> 2. git pull --ff-only
>>>> 
>>>> I'm simply from-scratch rebuilding what I'm
>>>> already running, based on main 7381bbee29df from
>>>> 2021-03-12:
>>>> 
>>>> # ~/fbsd-based-on-what-freebsd-main.sh 
>>>> merge-base: 7381bbee29df959e88ec59866cf2878263e7f3b2
>>>> merge-base: CommitDate: 2021-03-12 20:29:42 +0000
>>>> def0058cc690 (HEAD -> mm-src) mm-src snapshot for mm's patched build in git context.
>>>> 7381bbee29df (freebsd/main, freebsd/HEAD, pure-src, main) cam: Run all XPT_ASYNC ccbs in a dedicated thread
>>>> FreeBSD RPi4B 14.0-CURRENT FreeBSD 14.0-CURRENT mm-src-n245445-def0058cc690 GENERIC-NODBG  arm64 aarch64 1400005 1400005
>>>> 
>>>>>> 3. make -j10 cleanworld
>>>>>> 4. make -j10 cleandir
>>>>>> 5. make -j10 clean
>>>> 
>>>> My /usr/obj/cortexA72_clang/ was empty at the
>>>> start of the buildworld buildkernel .
>>>> devel/ccache is still not installed.
>>>> 
>>>>> This does not show ccache being cleared out
>>>>> before the below. So the times may be examples
>>>>> of "with ccache benefit" times. The contrast
>>>>> with mine and Bob P.'s times suggests a
>>>>> nice time-benefit can occur.
>>>>> 
>>>>>> 6. make -j6 buildworld
>>>>>> 7. make -j6 buildkernel
>>>> 
>>>> I'm using "-j6 buildworld buildkernel".
>>>> 
>>>>>> here's the src.conf :
>>>>>> https://cloud.zyxst.net/~john/FreeBSD/rpi4-main/src.conf
>>>> 
>>>> I'm using my normal src.conf equivalent, not
>>>> yours. (So the experiment is comparable to my
>>>> normal past experiments in this respect, matching
>>>> what I've reported in the past.)
>>>> 
>>>>> I seem to get intermittent access to
>>>>> https://cloud.zyxst.net/ but got to
>>>>> see the file content eventually.
>>>>> 
>>>>>> relevant rc.conf settings:
>>>>>> powerd_enable="YES"
>>>>>> powerd_flags="-r 1"
>>>> 
>>>> I commented out the config.txt line that assigned
>>>> arm_freq_min and the /etc/sysctl/conf line that
>>>> assigned an arm frequency.
> 
> I get to retry, attempting to actually do what I said
> I'd done for powerd enabling . . . I've rebooted and
> verified powerd now shows with the appropriate command
> line in top. So I've cleared things out in
> /usr/obj/cortexA72_clang/ and started a -j6 experiment
> as the first one.
> 
>>>> I put the 2 powerd_* lines above in my /etc/rc.conf .
>>>> 
>>>>>> sysctl.conf settings:
>>>>>> vfs.read_max=128 # default 64 # Cluster read-ahead max block count
>>>> 
>>>> I added the above line to my /etc/sysctl.conf .
>>>> 
>>>>>> config.txt:
>>>>>> kernel=u-boot.bin
>>>>>> over_voltage=6
>>>>>> arm_freq=2000
>>>>>> sdram_freq_min=3200
>>>> 
>>>> Ignoring comment differences, mine matches
>>>> for such lines.
>>>> 
>>>> I rebooted on the basis of all these changes
>>>> before starting the "-j6 buildworld buildkernel"
>>>> style build.
>>>> 
>>>>> Thanks much for the information.
>>>>> 
>>>> 
>>>> So, 6..10(?) of hours from when the
>>>> build started I should have time frames
>>>> to report for a "no ccache benefit"
>>>> build to compare to my past reported
>>>> build times.
>>>> 

With powerd actually enabled ("-r 1") this time . . .

-j6 summary: Overall somewhat under 9 hrs historically
for -j4 in my non-powerd configuration turned into
somewhat under 6 hrs 45 min for -j6 in the test powerd
configuration, somewhat over 2 hr 10 min faster. 

I plan on a -j4 test in the context as well.

The -j6 details . . .
(builds are via a EtherNet ssh session)

First a reminder of the prior timing that I
reported for my normal configuration of my
normal -j4 buildworld buildkernel in my
usual overclocking style:

World build completed on Thu Mar 11 18:39:37 PST 2021
World built in 29780 seconds, ncpu: 4, make -j4
Kernel build for GENERIC-NODBG completed on Thu Mar 11 19:18:02 PST 2021
Kernel(s)  GENERIC-NODBG built in 2305 seconds, ncpu: 4, make -j4

So a few minutes under 9 hr total for my
normal configuration.

By contrast, for the -j6 powerd configuration in this
experiment:

World build completed on Thu Mar 25 16:52:56 PDT 2021
World built in 22324 seconds, ncpu: 4, make -j6
Kernel build for GENERIC-NODBG completed on Thu Mar 25 17:21:16 PDT 2021
Kernel(s)  GENERIC-NODBG built in 1700 seconds, ncpu: 4, make -j6

So somewhat under 6 hrs 45 min. Nice!
(It is a little bit faster than the total for
the build times that you reported.)

Interestingly, after the build and some idle time
I see no evidence of the CPUs being slowed down:

# sysctl dev.cpu.0.freq
dev.cpu.0.freq: 2000

# sysctl hw.cpufreq.arm_freq
hw.cpufreq.arm_freq: 2000000000

For reference: the cpu's had definitely cooled
(from the low 50C's range):

# sysctl hw.cpufreq.temperature
hw.cpufreq.temperature: 37447

# sysctl dev.cpu.0.temperature
dev.cpu.0.temperature: 36.4C

Also:

# sysctl dev.bcm2835_cpufreq.0.freq_settings
dev.bcm2835_cpufreq.0.freq_settings: 2000/-1 600/-1

# sysctl dev.cpu.0.freq_levels
dev.cpu.0.freq_levels: 2000/-1 600/-1

[Fedora gives a much longer list (in other
units) when the minimum is not forced:
int f over 6<=f<=20: (f*100)*1MHz . But, as
I remember, other linux OS's gave an even
different list. Seems to be a choice as to
what possibilities to expose of many
that can be set up.]

I note that sysctl reports:

# sysctl hw.cpufreq.turbo
hw.cpufreq.turbo: 1

I'm not sure of the value that shows up in in my normal
configuration but I do not explicitly set it in any
configuration.

FYI: my modified version of top reported Maximum
Observed for Active+Wired of: 3468Mi MaxObs(Act+Wir),
suggesting that a 4 GiByte RPi4B might be a little
constrained at some point(s) in the build by the more
limited RAM and 2 GiByte RPi4B's or less would be
constrained for sure.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)