From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- Documentation/admin-guide/mm/cma_debugfs.rst | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 Documentation/admin-guide/mm/cma_debugfs.rst (limited to 'Documentation/admin-guide/mm/cma_debugfs.rst') diff --git a/Documentation/admin-guide/mm/cma_debugfs.rst b/Documentation/admin-guide/mm/cma_debugfs.rst new file mode 100644 index 000000000..7367e6294 --- /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 area represents a directory under /cma/, represented by +its CMA name like below: + + /cma/ + +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 > /cma//alloc + +would try to allocate 5 pages from the 'cma_name' area. + + - [WO] free: Free N pages from that CMA area, similar to the above. -- cgit v1.2.3