Commit 10d18135 authored by Mike Rapoport (IBM)'s avatar Mike Rapoport (IBM) Committed by Jonathan Corbet
Browse files

docs/mm: Physical Memory: add example of interleaving nodes 



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: default avatarMichal Hocko <mhocko@kernel.org>
Signed-off-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20230213154447.1631847-1-rppt@kernel.org


Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 33fcc0e3

Documentation/mm/physical_memory.rst

+19 −0
Original line number Diff line number Diff line
@@ -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