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Date:   Thu, 27 Jun 2019 08:54:49 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     subhra mazumdar <subhra.mazumdar@oracle.com>
cc:     linux-kernel@vger.kernel.org, peterz@infradead.org,
        mingo@redhat.com, steven.sistare@oracle.com,
        dhaval.giani@oracle.com, daniel.lezcano@linaro.org,
        vincent.guittot@linaro.org, viresh.kumar@linaro.org,
        tim.c.chen@linux.intel.com, mgorman@techsingularity.net
Subject: Re: [PATCH v3 6/7] x86/smpboot: introduce per-cpu variable for HT
 siblings
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References: <20190627012919.4341-1-subhra.mazumdar@oracle.com> <20190627012919.4341-7-subhra.mazumdar@oracle.com> <alpine.DEB.2.21.1906270844500.32342@nanos.tec.linutronix.de>
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On Thu, 27 Jun 2019, Thomas Gleixner wrote:

> On Wed, 26 Jun 2019, subhra mazumdar wrote:
> 
> > Introduce a per-cpu variable to keep the number of HT siblings of a cpu.
> > This will be used for quick lookup in select_idle_cpu to determine the
> > limits of search.
> 
> Why? The number of siblings is constant at least today unless you play
> silly cpu hotplug games. A bit more justification for adding yet another
> random storage would be appreciated.
> 
> > This patch does it only for x86.
> 
> # grep 'This patch' Documentation/process/submitting-patches.rst
> 
> IOW, we all know already that this is a patch and from the subject prefix
> and the diffstat it's pretty obvious that this is x86 only.
> 
> So instead of documenting the obvious, please add proper context to justify
> the change.

Aside of that the right ordering is to introduce the default fallback in a
separate patch, which explains the reasoning and then in the next one add
the x86 optimized version.

Thanks,

	tglx