From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx> 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 <mhocko@xxxxxxxxxx> Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx> --- v2: * Wording update (Bagas) * Add forgotten Suggested-by v1: https://lore.kernel.org/all/20230211102207.1267058-1-rppt@xxxxxxxxxx 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..d14b785fd938 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 | +---------+----------+-----------+ +------------+-------------+ + +Note, that memory banks may belong to interleaving nodes. In the example +below an x86 machine has 16Gbytes or 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 such 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
