Date:   Tue, 24 Jan 2023 14:40:54 +0100
From:   Vlastimil Babka <vbabka@suse.cz>
To:     Mike Rapoport <rppt@kernel.org>
CC:     Jonathan Corbet <corbet@lwn.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Bagas Sanjaya <bagasdotme@gmail.com>,
        David Hildenbrand <david@redhat.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Lorenzo Stoakes <lstoakes@gmail.com>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@kernel.org>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Michal Hocko <mhocko@suse.com>
Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_v4_1/1=5D_docs/mm=3A_Physical_Memory=3A_ad?= =?US-ASCII?Q?d_structure=2C_introduction_and_nodes_description?=
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On January 24, 2023 12:16:20 PM GMT+01:00, Mike Rapoport <rppt@kernel=2Eor=
g> wrote:
>On Tue, Jan 24, 2023 at 12:00:07PM +0100, Vlastimil Babka wrote:
>> On 1/15/23 19:42, Mike Rapoport wrote:
>> > From: "Mike Rapoport (IBM)" <rppt@kernel=2Eorg>
>> >=20
>> > Add structure, introduction and Nodes section to Physical Memory
>> > chapter=2E
>> >=20
>> > As the new documentation references core-api/dma-api and mm/page_recl=
aim,
>> > add page labels to those documents=2E
>> >=20
>> > Reviewed-by: Bagas Sanjaya <bagasdotme@gmail=2Ecom>
>> > Reviewed-by: Lorenzo Stoakes <lstoakes@gmail=2Ecom>
>> > Acked-by: Michal Hocko <mhocko@suse=2Ecom>
>> > Signed-off-by: Mike Rapoport (IBM) <rppt@kernel=2Eorg>
>>=20
>> Acked-by: Vlastimil Babka <vbabka@suse=2Ecz>
>>=20
>> A small bug to fix below?
>>=20
>> <snip>
>>=20
>> > +
>> > +Along with the node structures, kernel maintains an array of ``nodem=
ask_t``
>> > +bitmasks called ``node_states``=2E Each bitmask in this array repres=
ents a set of
>> > +nodes with particular properties as defined by ``enum node_states``:
>> > +
>> > +``N_POSSIBLE``
>> > +  The node could become online at some point=2E
>> > +``N_ONLINE``
>> > +  The node is online=2E
>> > +``N_NORMAL_MEMORY``
>> > +  The node has regular memory=2E
>> > +``N_HIGH_MEMORY``
>> > +  The node has regular or high memory=2E When ``CONFIG_HIGHMEM`` is =
disabled
>> > +  aliased to ``N_NORMAL_MEMORY``=2E
>>=20
>> Noted=2E
>>=20
>> > +``N_MEMORY``
>> > +  The node has memory(regular, high, movable)
>> > +``N_CPU``
>> > +  The node has one or more CPUs
>> > +
>> > +For each node that has a property described above, the bit correspon=
ding to the
>> > +node ID in the ``node_states[<property>]`` bitmask is set=2E
>> > +
>> > +For example, for node 2 with normal memory and CPUs, bit 2 will be s=
et in ::
>> > +
>> > +  node_states[N_POSSIBLE]
>> > +  node_states[N_ONLINE]
>> > +  node_states[N_NORMAL_MEMORY]
>> > +  node_states[N_MEMORY]
>> > +  node_states[N_CPU]
>>=20
>> Should it be set also in node_states[N_HIGH_MEMORY]?
>=20
>You mean because of the aliasing of N_NORMAL_MEMORY and N_HIGH_MEMORY?

No I meant due to "The node has regular or high memory=2E" Or do I misunde=
rstand?