Documentation/ABI/testing/sysfs-kernel-mm-cma
Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-kernel-mm-cma
File Facts
- System
- Linux kernel
- Corpus path
Documentation/ABI/testing/sysfs-kernel-mm-cma- Extension
[no extension]- Size
- 1329 bytes
- Lines
- 45
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: Documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
What: /sys/kernel/mm/cma/
Date: Feb 2021
Contact: Minchan Kim <minchan@kernel.org>
Description:
/sys/kernel/mm/cma/ contains a subdirectory for each CMA
heap name (also sometimes called CMA areas).
Each CMA heap subdirectory (that is, each
/sys/kernel/mm/cma/<cma-heap-name> directory) contains the
following items:
alloc_pages_success
alloc_pages_fail
What: /sys/kernel/mm/cma/<cma-heap-name>/alloc_pages_success
Date: Feb 2021
Contact: Minchan Kim <minchan@kernel.org>
Description:
the number of pages CMA API succeeded to allocate
What: /sys/kernel/mm/cma/<cma-heap-name>/alloc_pages_fail
Date: Feb 2021
Contact: Minchan Kim <minchan@kernel.org>
Description:
the number of pages CMA API failed to allocate
What: /sys/kernel/mm/cma/<cma-heap-name>/release_pages_success
Date: Feb 2024
Contact: Anshuman Khandual <anshuman.khandual@arm.com>
Description:
the number of pages CMA API succeeded to release
What: /sys/kernel/mm/cma/<cma-heap-name>/total_pages
Date: Jun 2024
Contact: Frank van der Linden <fvdl@google.com>
Description:
The size of the CMA area in pages.
What: /sys/kernel/mm/cma/<cma-heap-name>/available_pages
Date: Jun 2024
Contact: Frank van der Linden <fvdl@google.com>
Description:
The number of pages in the CMA area that are still
available for CMA allocation.Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.