RE: [PATCH v2 0/2] cpufreq: Specify the default governor on command line

From: "Doug Smythies" <dsmythies@telus.net>
To: "'Quentin Perret'" <qperret@google.com>
Cc: <arnd@arndb.de>, <mpe@ellerman.id.au>, <benh@kernel.crashing.org>,
	<paulus@samba.org>, <mingo@redhat.com>, <peterz@infradead.org>,
	<juri.lelli@redhat.com>, <vincent.guittot@linaro.org>,
	<linuxppc-dev@lists.ozlabs.org>, <linux-kernel@vger.kernel.org>,
	<linux-pm@vger.kernel.org>, <kernel-team@android.com>,
	<tkjos@google.com>, <adharmap@codeaurora.org>,
	<viresh.kumar@linaro.org>, <rafael@kernel.org>,
	<rjw@rjwysocki.net>
Subject: RE: [PATCH v2 0/2] cpufreq: Specify the default governor on command line
Date: Tue, 23 Jun 2020 17:07:52 -0700	[thread overview]
Message-ID: <002e01d649bb$849b71a0$8dd254e0$@net> (raw)
In-Reply-To: <20200623180437.GA248517@google.com>

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Hi Quentin,
Thanks for your quick reply.

On 2020.06.23 11:05 Quentin Perret wrote: 

> Hi Doug,
> 
> On Tuesday 23 Jun 2020 at 10:54:33 (-0700), Doug Smythies wrote:
> > Hi Quentin,
> >
> > Because I am lazy and sometimes do not want to recompile
> > the distro source, I have a need/desire for this.
> 
> Good to know I'm not the only one ;-)
> 
> > Tested these two grub command lines:
> >
> > GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1 consoleblank=300 intel_pstate=disable
> cpufreq.default_governor=schedutil cpuidle_sysfs_switch cpuidle.governor=teo"
> >
> > And
> >
> > #GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1 consoleblank=450 intel_pstate=passive
> cpufreq.default_governor=schedutil cpuidle_sysfs_switch cpuidle.governor=teo"
> >
> > And all worked as expected. I use Ubuntu as my distro, and also had to disable a startup script that
> switches to "ondemand", or similar, after 1 minute.
> 
> Good, thanks for giving it a try.
> 
> > As a side note (separate subject, but is one reason I tried it):
> > My i5-9600K based computer seems to hit a power limit during boot approximately 3 seconds after
> kernel selection on grub.
> > This had no effect on that issue (even when selecting powersave governor).
> 
> Interesting ... Could you confirm that compiling with powersave as
> default doesn't fix the issue either?

No, it doesn't (good idea for a test though).
However, the big mains spike is also gone. So, I no longer know why those power
limit log bits are always set after boot.

> 
> Other question, when does the intel_pstate driver start on your device?
> Before or after that 3 seconds boot time?

Before, if I understand correctly (from dmesg):

[    0.468969] intel_pstate: Intel P-state driver initializing

I'll attach a couple of annotated mains power graphs.
(which will likely get stripped from the on-list version of this e-mail).

Currently, I am drowning in stuff that doesn't work, and will put
this aside for now. I'll revive this as a new thread or a bugzilla
eventually.

I also tried booting with turbo disabled, no difference.

Thanks for this patch set.

... Doug

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