Subject: Re: [PATCH v3] mm, sysctl: make NUMA stats configurable
To: Andrew Morton <akpm@linux-foundation.org>,
        Kemi Wang <kemi.wang@intel.com>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>,
        Kees Cook <keescook@chromium.org>, Jonathan Corbet <corbet@lwn.net>,
        Michal Hocko <mhocko@suse.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Christopher Lameter <cl@linux.com>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Dave <dave.hansen@linux.intel.com>, Tim Chen <tim.c.chen@intel.com>,
        Andi Kleen <andi.kleen@intel.com>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Ying Huang <ying.huang@intel.com>, Aaron Lu <aaron.lu@intel.com>,
        Proc sysctl <linux-fsdevel@vger.kernel.org>,
        Linux MM <linux-mm@kvack.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>
References: <1506579101-5457-1-git-send-email-kemi.wang@intel.com>
 <20170928142950.1a09090fe4baf4acdc1bbc35@linux-foundation.org>
From: Vlastimil Babka <vbabka@suse.cz>
Message-ID: <ce5e160c-0105-71d2-d95d-497c92e0f936@suse.cz>
Date: Fri, 29 Sep 2017 09:09:40 +0200
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On 09/28/2017 11:29 PM, Andrew Morton wrote:
> On Thu, 28 Sep 2017 14:11:41 +0800 Kemi Wang <kemi.wang@intel.com> wrote:
> 
>> This is the second step which introduces a tunable interface that allow
>> numa stats configurable for optimizing zone_statistics(), as suggested by
>> Dave Hansen and Ying Huang.
> 
> Looks OK I guess.
> 
> I fiddled with it a lot.  Please consider:
> 
> From: Andrew Morton <akpm@linux-foundation.org>
> Subject: mm-sysctl-make-numa-stats-configurable-fix
> 
> - tweak documentation
> 
> - move advisory message from start_kernel() into mm_init() (I'm not sure
>   we really need this message)

Actually, I'm not sure we need any of the current messages, or to have
them at higher priority than pr_debug()? They are all triggered by admin
action, or unconditionally upon boot.
OTOH I think that an useful message that's currently missing would be
when the static_key_enable() is triggered in auto mode. Bonus points for
including the name of the process and the stat file that was read.
However static_key_enable() returns void and not whether it actually
flipped the switch, so it's not trivial.