Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 9 Jun 2021 13:25:44 +0200
From:   Frederic Weisbecker <frederic@kernel.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Ingo Molnar <mingo@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] sched: Add default dynamic preempt mode Kconfig
Message-ID: <20210609112544.GB104634@lothringen>
References: <20210608120442.93587-1-frederic@kernel.org>
 <20210608120442.93587-2-frederic@kernel.org>
 <YL9271QMQfyn174k@hirez.programming.kicks-ass.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <YL9271QMQfyn174k@hirez.programming.kicks-ass.net>
Precedence: bulk

On Tue, Jun 08, 2021 at 03:55:59PM +0200, Peter Zijlstra wrote:
> On Tue, Jun 08, 2021 at 02:04:41PM +0200, Frederic Weisbecker wrote:
> > diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> > index 9e9a5be35cde..df47a8275c37 100644
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -6238,6 +6238,14 @@ enum {
> >  
> >  int preempt_dynamic_mode = preempt_dynamic_full;
> >  
> > +#if defined(CONFIG_PREEMPT_DYNAMIC_FULL)
> > +static __initdata int preempt_dynamic_mode_init = preempt_dynamic_full;
> > +#elif defined(CONFIG_PREEMPT_DYNAMIC_VOLUNTARY)
> > +static __initdata int preempt_dynamic_mode_init = preempt_dynamic_voluntary;
> > +#elif defined(CONFIG_PREEMPT_DYNAMIC_NONE)
> > +static __initdata int preempt_dynamic_mode_init = preempt_dynamic_none;
> > +#endif
> 
> Why does preempt_dynamic_mode_init exist? Why can't we simply set
> preempt_dynamic_mode?

To avoid the unconditional calls to static_call_update() on boot but I can do
it in a more simple way.

Thanks.