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From:   Valentin Schneider <valentin.schneider@arm.com>
To:     Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc:     Thara Gopinath <thara.gopinath@linaro.org>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: v5.7: new core kernel option missing help text
In-reply-to: <20200604092901.GE1551@shell.armlinux.org.uk>
Date:   Thu, 04 Jun 2020 11:56:06 +0100
Message-ID: <jhjbllzhzg9.mognet@arm.com>
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On 04/06/20 10:29, Russell King - ARM Linux admin wrote:
> On Thu, Jun 04, 2020 at 10:26:27AM +0100, Valentin Schneider wrote:
>>
>> On 04/06/20 01:48, Thara Gopinath wrote:
>> > Hi Russel/Valentin
>> >
>> > The feature itself like Valentin explained below allows scheduler to be
>> > aware of cpu capacity reduced due to thermal throttling.
>> > arch_set_thermal_pressure feeds the capped capacity to the scheduler and
>> > hence the feature makes sense only if arch_set_thermal_pressure is
>> > implemented. Having said that arch_set_thermal_pressure is implemented
>> > in arch_topology driver for arm and arm64 platforms. But the feature
>> > itself is not bound to arm/arm64 platforms. So it would make it wrong to
>> > add a "depends on (ARM || ARM64) option."
>> >
>> > I agree with Vincent that allowing user to choose this option is
>> > probably not the best. IMO, this should be enabled by default in arm64
>> > defconfig considering both GENERIC_ARCH_TOPOLOGY and CPU_FREQ_THERMAL
>> > are enabled by default.
>>
>> Right, I had skimmed over that but it probably does make more sense not
>> to bother users with it.
>>
>> > So if it is acceptable three things to be done are:
>> > 1. Add the help text.
>> > 2. Don't allow SCHED_THERMAL_PRESSURE configurable by user
>> > 3. Enable it by default in arm64 defconfig
>>
>> ... and arm as well, I suppose?
>
> If it's not a user visible option, then there's no point it being in
> defconfig.

Right, s/defconfig/arch kconfig/ or somesuch.