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Message-ID: <beec14cee84de7a4bedd7a63c2acdf150a82bc09.camel@gmx.de>
Subject: Re: [PATCH] sched: Split preemption model selection between DYNAMIC
 & !DYNAMIC
From:   Mike Galbraith <efault@gmx.de>
To:     Frederic Weisbecker <frederic@kernel.org>,
        Valentin Schneider <valentin.schneider@arm.com>
Cc:     linux-kernel@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>
Date:   Wed, 10 Nov 2021 05:37:48 +0100
In-Reply-To: <20211110011738.GD288354@lothringen>
References: <20211109151057.3489223-1-valentin.schneider@arm.com>
         <20211110011738.GD288354@lothringen>
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On Wed, 2021-11-10 at 02:17 +0100, Frederic Weisbecker wrote:
> On Tue, Nov 09, 2021 at 03:10:57PM +0000, Valentin Schneider wrote:
> > +choice
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0prompt "Default boot-time P=
reemption Model"
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0depends on PREEMPT_DYNAMIC
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0default PREEMPT_NONE_BEHAVI=
OUR
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0help
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 This option defines =
the default preemption model of the kernel
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if it hasn't been sp=
ecified by the "preempt=3D" command line parameter.
> > =C2=A0
> > -config PREEMPT_VOLUNTARY
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0bool
> > +config PREEMPT_NONE_BEHAVIOUR
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0bool "No Forced Preemption =
(Server)"
> > =C2=A0
> > -config PREEMPT
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0bool
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0select PREEMPTION
> > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0select UNINLINE_SPIN_UNLOCK=
 if !ARCH_INLINE_SPIN_UNLOCK
> > +config PREEMPT_VOLUNTARY_BEHAVIOUR
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0bool "Voluntary Kernel Pree=
mption (Desktop)"
> > +
> > +config PREEMPT_BEHAVIOUR
> > +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0bool "Preemptible Kernel (L=
ow-Latency Desktop)"
> > +endchoice
>
> The problem here is that you're duplicating the existing titles
> for the static entries and you're losing all the help that text that use=
d to come
> along. The point of the BEHAVIOUR thing, further mapping to either
> static or dynamic preemption, was to avoid that duplication and keep the
> same titles and help for the three behaviour, whether static or dynamic.

Adding "depends on !PREEMPT_DYNAMIC" to the first (legacy?) choice made
it appear/disappear at the appropriate time as well, but I have no idea
how duplication of help text can be avoided.

	-Mike