[v3] docs/mm: Physical Memory: add example of interleaving nodes

Commit Message

Mike Rapoport Feb. 13, 2023, 3:44 p.m. UTC

From: "Mike Rapoport (IBM)" <[e-mail]>

Add an example of memory layout with interleaving nodes where even memory
banks belong to node 0 and odd memory banks belong to node 1

Suggested-by: Michal Hocko <[e-mail]>
Signed-off-by: Mike Rapoport (IBM) <[e-mail]>
---

v3:
* Fix typos and wording (Matthew) 

v2: https://lore.kernel.org/all/[e-mail]
* Wording update (Bagas)
* Add forgotten Suggested-by

v1: https://lore.kernel.org/all/[e-mail]
 Documentation/mm/physical_memory.rst | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)


base-commit: e076f253283c3e55a128fa9665c0e6cd8146948d

Comments

David Hildenbrand Feb. 13, 2023, 3:52 p.m. UTC | #1

On 13.02.23 16:44, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[e-mail]>
> 
> Add an example of memory layout with interleaving nodes where even memory
> banks belong to node 0 and odd memory banks belong to node 1
> 
> Suggested-by: Michal Hocko <[e-mail]>
> Signed-off-by: Mike Rapoport (IBM) <[e-mail]>
> ---

Reviewed-by: David Hildenbrand <[e-mail]>

Mike Rapoport Feb. 21, 2023, 6:52 a.m. UTC | #2

Ping?

On Mon, Feb 13, 2023 at 05:44:47PM +0200, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[e-mail]>
> 
> Add an example of memory layout with interleaving nodes where even memory
> banks belong to node 0 and odd memory banks belong to node 1
> 
> Suggested-by: Michal Hocko <[e-mail]>
> Signed-off-by: Mike Rapoport (IBM) <[e-mail]>
> ---
> 
> v3:
> * Fix typos and wording (Matthew) 
> 
> v2: https://lore.kernel.org/all/[e-mail]
> * Wording update (Bagas)
> * Add forgotten Suggested-by
> 
> v1: https://lore.kernel.org/all/[e-mail]
>  Documentation/mm/physical_memory.rst | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/Documentation/mm/physical_memory.rst b/Documentation/mm/physical_memory.rst
> index 3f3c02aa6e6e..863ddcd0b291 100644
> --- a/Documentation/mm/physical_memory.rst
> +++ b/Documentation/mm/physical_memory.rst
> @@ -114,6 +114,25 @@ RAM equally split between two nodes, there will be ``ZONE_DMA32``,
>    |  DMA32  |  NORMAL  |  MOVABLE  | |   NORMAL   |   MOVABLE   |
>    +---------+----------+-----------+ +------------+-------------+
>  
> +
> +Memory banks may belong to interleaving nodes. In the example below an x86
> +machine has 16 Gbytes of RAM in 4 memory banks, even banks belong to node 0
> +and odd banks belong to node 1::
> +
> +
> +  0              4G              8G             12G            16G
> +  +-------------+ +-------------+ +-------------+ +-------------+
> +  |    node 0   | |    node 1   | |    node 0   | |    node 1   |
> +  +-------------+ +-------------+ +-------------+ +-------------+
> +
> +  0   16M      4G
> +  +-----+-------+ +-------------+ +-------------+ +-------------+
> +  | DMA | DMA32 | |    NORMAL   | |    NORMAL   | |    NORMAL   |
> +  +-----+-------+ +-------------+ +-------------+ +-------------+
> +
> +In this case node 0 will span from 0 to 12 Gbytes and node 1 will span from
> +4 to 16 Gbytes.
> +
>  .. _nodes:
>  
>  Nodes
> 
> base-commit: e076f253283c3e55a128fa9665c0e6cd8146948d
> -- 
> 2.35.1
>

Jonathan Corbet Feb. 21, 2023, 2:31 p.m. UTC | #3

Mike Rapoport <[e-mail]> writes:

> Ping?

It's in my queue.  The docs tree has conflicts all over the place this
time around, so I closed things down a bit earlier than I otherwise
would have.  I'm expecting to catch up a bit in the coming week.

Thanks,

jon

Jonathan Corbet March 14, 2023, 6:54 p.m. UTC | #4

Mike Rapoport <[e-mail]> writes:

> From: "Mike Rapoport (IBM)" <[e-mail]>
>
> Add an example of memory layout with interleaving nodes where even memory
> banks belong to node 0 and odd memory banks belong to node 1
>
> Suggested-by: Michal Hocko <[e-mail]>
> Signed-off-by: Mike Rapoport (IBM) <[e-mail]>
> ---
>
> v3:
> * Fix typos and wording (Matthew) 
>
> v2: https://lore.kernel.org/all/[e-mail]
> * Wording update (Bagas)
> * Add forgotten Suggested-by
>
> v1: https://lore.kernel.org/all/[e-mail]
>  Documentation/mm/physical_memory.rst | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)

Applied (finally).  Thanks and apologies for the delay,

jon

Patch

diff --git a/Documentation/mm/physical_memory.rst b/Documentation/mm/physical_memory.rst
index 3f3c02aa6e6e..863ddcd0b291 100644
--- a/Documentation/mm/physical_memory.rst
+++ b/Documentation/mm/physical_memory.rst
@@ -114,6 +114,25 @@  RAM equally split between two nodes, there will be ``ZONE_DMA32``,
   |  DMA32  |  NORMAL  |  MOVABLE  | |   NORMAL   |   MOVABLE   |
   +---------+----------+-----------+ +------------+-------------+
 
+
+Memory banks may belong to interleaving nodes. In the example below an x86
+machine has 16 Gbytes of RAM in 4 memory banks, even banks belong to node 0
+and odd banks belong to node 1::
+
+
+  0              4G              8G             12G            16G
+  +-------------+ +-------------+ +-------------+ +-------------+
+  |    node 0   | |    node 1   | |    node 0   | |    node 1   |
+  +-------------+ +-------------+ +-------------+ +-------------+
+
+  0   16M      4G
+  +-----+-------+ +-------------+ +-------------+ +-------------+
+  | DMA | DMA32 | |    NORMAL   | |    NORMAL   | |    NORMAL   |
+  +-----+-------+ +-------------+ +-------------+ +-------------+
+
+In this case node 0 will span from 0 to 12 Gbytes and node 1 will span from
+4 to 16 Gbytes.
+
 .. _nodes:
 
 Nodes