26 lines
882 B
ReStructuredText
26 lines
882 B
ReStructuredText
=====================
|
|
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 <debugfs>/cma/, represented by
|
|
its CMA name like below:
|
|
|
|
<debugfs>/cma/<cma_name>
|
|
|
|
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_name>/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.
|