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Date: Tue, 10 Mar 2026 13:17:26 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Barry Song <21cnbao@gmail.com>
Cc: Breno Leitao <leitao@debian.org>, David Hildenbrand <david@kernel.org>,
 Lorenzo Stoakes <lorenzo.stoakes@oracle.com>, Zi Yan <ziy@nvidia.com>,
 Baolin Wang <baolin.wang@linux.alibaba.com>, "Liam R. Howlett"
 <Liam.Howlett@oracle.com>, Nico Pache <npache@redhat.com>, Ryan Roberts
 <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>, Lance Yang
 <lance.yang@linux.dev>, Vlastimil Babka <vbabka@kernel.org>, Suren
 Baghdasaryan <surenb@google.com>, Michal Hocko <mhocko@suse.com>, Brendan
 Jackman <jackmanb@google.com>, Johannes Weiner <hannes@cmpxchg.org>, Mike
 Rapoport <rppt@kernel.org>, linux-mm@kvack.org,
 linux-kernel@vger.kernel.org, usamaarif642@gmail.com, kas@kernel.org,
 kernel-team@meta.com, "Lorenzo Stoakes (Oracle)" <ljs@kernel.org>
Subject: Re: [PATCH v5 2/4] mm: huge_memory: refactor anon_enabled_store()
 with change_anon_orders()
Message-Id: <20260310131726.a9173c7cfa333b6522f9c8f2@linux-foundation.org>
In-Reply-To: <CAGsJ_4zUQPfrpnwcXJQUGMP_0dUW7uQpVuGr7EfNm+qPnDGLHA@mail.gmail.com>
References: <20260310-thp_logs-v5-0-686099175bf6@debian.org>
	<20260310-thp_logs-v5-2-686099175bf6@debian.org>
	<CAGsJ_4zUQPfrpnwcXJQUGMP_0dUW7uQpVuGr7EfNm+qPnDGLHA@mail.gmail.com>
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On Wed, 11 Mar 2026 04:11:36 +0800 Barry Song <21cnbao@gmail.com> wrote:

> > +static bool set_anon_enabled_mode(int order, enum anon_enabled_mode mode)
> > +{
> > +       static unsigned long *enabled_orders[] = {
> > +               &huge_anon_orders_always,
> > +               &huge_anon_orders_madvise,
> > +               &huge_anon_orders_inherit,
> > +       };
> 
> Is there a reason enabled_orders needs to be static?
> Could it instead be allocated on the stack?

Could, but then the array would be rebuilt each time the function is called.
The idea here is to save a bit of runtime cost.