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authorMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-06-27 14:56:51 -0300
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-07-15 11:03:02 -0300
commit4f4cfa6c560c93ba180c30675cf845e1597de44c (patch)
tree0bbe2ec9e6ef62ed2a347504dda50c6bdbe43703 /Documentation/admin-guide/mm
parentda82c92f1150f66afabf78d2c85ef9ac18dc6d38 (diff)
docs: admin-guide: add a series of orphaned documents
There are lots of documents that belong to the admin-guide but are on random places (most under Documentation root dir). Move them to the admin guide. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Diffstat (limited to 'Documentation/admin-guide/mm')
-rw-r--r--Documentation/admin-guide/mm/cma_debugfs.rst25
-rw-r--r--Documentation/admin-guide/mm/index.rst1
2 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/admin-guide/mm/cma_debugfs.rst b/Documentation/admin-guide/mm/cma_debugfs.rst
new file mode 100644
index 000000000000..4e06ffabd78a
--- /dev/null
+++ b/Documentation/admin-guide/mm/cma_debugfs.rst
@@ -0,0 +1,25 @@
+=====================
+CMA Debugfs Interface
+=====================
+
+The CMA debugfs interface is useful to retrieve basic information out of the
+different CMA areas and to test allocation/release in each of the areas.
+
+Each CMA zone represents a directory under <debugfs>/cma/, indexed by the
+kernel's CMA index. So the first CMA zone would be:
+
+ <debugfs>/cma/cma-0
+
+The structure of the files created under that directory is as follows:
+
+ - [RO] base_pfn: The base PFN (Page Frame Number) of the zone.
+ - [RO] count: Amount of memory in the CMA area.
+ - [RO] order_per_bit: Order of pages represented by one bit.
+ - [RO] bitmap: The bitmap of page states in the zone.
+ - [WO] alloc: Allocate N pages from that CMA area. For example::
+
+ echo 5 > <debugfs>/cma/cma-2/alloc
+
+would try to allocate 5 pages from the cma-2 area.
+
+ - [WO] free: Free N pages from that CMA area, similar to the above.
diff --git a/Documentation/admin-guide/mm/index.rst b/Documentation/admin-guide/mm/index.rst
index 5f61a6c429e0..11db46448354 100644
--- a/Documentation/admin-guide/mm/index.rst
+++ b/Documentation/admin-guide/mm/index.rst
@@ -26,6 +26,7 @@ the Linux memory management.
:maxdepth: 1
concepts
+ cma_debugfs
hugetlbpage
idle_page_tracking
ksm