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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-24 12:35:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-04-24 12:35:49 -0700 |
commit | c23f28975abc2eb02cecc8bc1f2c95473a59ed2e (patch) | |
tree | d356762219c0d3079d37f1cc3ab3eef5cd37567a /Documentation/mm | |
parent | 1be89faab3cf1f3dd6eb4924b60d2b9094e7206b (diff) | |
parent | 7e8472c820f04517ae5d5a27c1aecfa2263a0aa5 (diff) | |
download | linux-rpi-c23f28975abc2eb02cecc8bc1f2c95473a59ed2e.tar.gz linux-rpi-c23f28975abc2eb02cecc8bc1f2c95473a59ed2e.tar.bz2 linux-rpi-c23f28975abc2eb02cecc8bc1f2c95473a59ed2e.zip |
Merge tag 'docs-6.4' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"Commit volume in documentation is relatively low this time, but there
is still a fair amount going on, including:
- Reorganize the architecture-specific documentation under
Documentation/arch
This makes the structure match the source directory and helps to
clean up the mess that is the top-level Documentation directory a
bit. This work creates the new directory and moves x86 and most of
the less-active architectures there.
The current plan is to move the rest of the architectures in 6.5,
with the patches going through the appropriate subsystem trees.
- Some more Spanish translations and maintenance of the Italian
translation
- A new "Kernel contribution maturity model" document from Ted
- A new tutorial on quickly building a trimmed kernel from Thorsten
Plus the usual set of updates and fixes"
* tag 'docs-6.4' of git://git.lwn.net/linux: (47 commits)
media: Adjust column width for pdfdocs
media: Fix building pdfdocs
docs: clk: add documentation to log which clocks have been disabled
docs: trace: Fix typo in ftrace.rst
Documentation/process: always CC responsible lists
docs: kmemleak: adjust to config renaming
ELF: document some de-facto PT_* ABI quirks
Documentation: arm: remove stih415/stih416 related entries
docs: turn off "smart quotes" in the HTML build
Documentation: firmware: Clarify firmware path usage
docs/mm: Physical Memory: Fix grammar
Documentation: Add document for false sharing
dma-api-howto: typo fix
docs: move m68k architecture documentation under Documentation/arch/
docs: move parisc documentation under Documentation/arch/
docs: move ia64 architecture docs under Documentation/arch/
docs: Move arc architecture docs under Documentation/arch/
docs: move nios2 documentation under Documentation/arch/
docs: move openrisc documentation under Documentation/arch/
docs: move superh documentation under Documentation/arch/
...
Diffstat (limited to 'Documentation/mm')
-rw-r--r-- | Documentation/mm/physical_memory.rst | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/Documentation/mm/physical_memory.rst b/Documentation/mm/physical_memory.rst index 1bc888d36ea1..531e73b003dd 100644 --- a/Documentation/mm/physical_memory.rst +++ b/Documentation/mm/physical_memory.rst @@ -19,7 +19,7 @@ a bank of memory very suitable for DMA near peripheral devices. Each bank is called a node and the concept is represented under Linux by a ``struct pglist_data`` even if the architecture is UMA. This structure is -always referenced to by it's typedef ``pg_data_t``. ``A pg_data_t`` structure +always referenced by its typedef ``pg_data_t``. A ``pg_data_t`` structure for a particular node can be referenced by ``NODE_DATA(nid)`` macro where ``nid`` is the ID of that node. @@ -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 |