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From:   Valentin Schneider <valentin.schneider@arm.com>
To:     Vincent Guittot <vincent.guittot@linaro.org>
Cc:     linux-kernel <linux-kernel@vger.kernel.org>,
        Rik van Riel <riel@surriel.com>,
        Qais Yousef <qais.yousef@arm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Quentin Perret <qperret@google.com>,
        Pavan Kondeti <pkondeti@codeaurora.org>,
        Lingutla Chandrasekhar <clingutla@codeaurora.org>
Subject: Re: [PATCH v3 3/7] sched/fair: Add more sched_asym_cpucapacity static branch checks
In-Reply-To: <CAKfTPtC-=PYTy5c6iOEwU=53S+gAYVzc6=GMTyEzjQWuyk7_uQ@mail.gmail.com>
References: <20210311120527.167870-1-valentin.schneider@arm.com> <20210311120527.167870-4-valentin.schneider@arm.com> <CAKfTPtC-=PYTy5c6iOEwU=53S+gAYVzc6=GMTyEzjQWuyk7_uQ@mail.gmail.com>
Date:   Mon, 15 Mar 2021 19:24:29 +0000
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Hi Vincent,

Thanks for taking another look at this.

On 15/03/21 15:18, Vincent Guittot wrote:
> On Thu, 11 Mar 2021 at 13:05, Valentin Schneider
> <valentin.schneider@arm.com> wrote:
>>
>> Rik noted a while back that a handful of
>>
>>   sd->flags & SD_ASYM_CPUCAPACITY
>>
>> & family in the CFS load-balancer code aren't guarded by the
>> sched_asym_cpucapacity static branch.
>
> guarding asym capacity with static branch in fast path makes sense but
> I see no benefit in this slow path but hiding and complexifying the
> code. Also if you start with this way then you have to add a nop in
> all other places where flag or a group_type might be unused.
>

OK, fair enough, I'll drop this one.