Date: Mon, 12 Jul 2021 23:17:09 -0400 From: Paul Procacci <pprocacci@gmail.com> To: "Thomas D. Dean" <tomdean@wavecable.com> Cc: FreeBSD Questions <freebsd-questions@freebsd.org> Subject: Re: How do I disable CPU throttling Message-ID: <CAFbbPuh5aCUF_07y-fiyg7kxRxSOCNQHAtSTDPQYrZQpA4HsOQ@mail.gmail.com> In-Reply-To: <4d1e32fc-3e77-626e-138b-6af872445c5e@wavecable.com> References: <f982b8fd-0ec0-24a9-8272-4da3bd5d19c4@wavecable.com> <0be4883a-6bf6-28bc-a14b-9cb1f6d729ae@wavecable.com> <CAFbbPuhuWdzjfH2e7RSwiUa2UORAoJE_-yQeqyoMz7gTMjfxTA@mail.gmail.com> <4d1e32fc-3e77-626e-138b-6af872445c5e@wavecable.com>
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On Mon, Jul 12, 2021 at 5:01 PM Thomas D. Dean <tomdean@wavecable.com>
wrote:
> On 7/12/21 1:12 PM, Paul Procacci wrote:
> > sysctl's get set generally in /etc/sysctl.conf
> >
> > dev.cpu.0.freq_levels <-- This format is called a mib in the native
> > parlance.
> > sysctl.conf(5) and sysctl(8) go into much further detail.
> >
> > ~Paul
>
>
> > grep -Rail freq_levels /etc/*
> shows the source of freq_levels
>
> I believe this is hardwired somewhere. Maybe read from the cpu? BIOS?
>
>
Most mib's have defaults. They are compiled into the kernel statically or
made available to it via kernel modules.
What you are looking for is located in this source file:
/usr/src/sys/kern/kern_cpu.c
Really though, I can tell that's way too much for ya. Instead what you are
looking to do is
detailed in rc.conf(5):
" powerd_enable
(bool) If set to "YES", enable the system power control
facility with the powerd(8) daemon."
AND
" performance_cpu_freq
(str) CPU clock frequency to use while on AC power. The
string "LOW" indicates that cpufreq(4) should use the
lowest
frequency available while "HIGH" indicates that the highest
frequency (less power savings) should be used."
What you want to most likely do is the following:
echo powerd_enable=\"YES\" >> /etc/rc.conf
echo performance_cpu_freq=\"HGH\" >> /etc/rc.conf
Follow that up by restarting the powerd daemon:
/etc/rc.d/powerd restart
If you have a supported cpu, which I have no reason to believe otherwise,
your
goal of running your machine at full speed without throttling should be
within your grasp.
powerd, a userland daemon, controls this mib as necessary on the fly.
rc.conf(5) is a godsend for stuff like this and its documentation is
amazing.
On another note, I see no reason to change this at all. CPU's are nearly
instantaneous
at scaling as necessary to accomodate loads for their needs. I digress
however.
Take Care.
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