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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-14 23:49:17 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-14 23:49:17 (GMT) |
commit | 1dcf58d6e6e6eb7ec10e9abc56887b040205b06f (patch) | |
tree | c03e7a25ef13eea62f1547914a76e5c68f3f4c28 /Documentation/cma | |
parent | 80dcc31fbe55932ac9204daee5f2ebc0c49b6da3 (diff) | |
parent | e4b0db72be2487bae0e3251c22f82c104f7c1cfd (diff) | |
download | linux-1dcf58d6e6e6eb7ec10e9abc56887b040205b06f.tar.xz |
Merge branch 'akpm' (patches from Andrew)
Merge first patchbomb from Andrew Morton:
- arch/sh updates
- ocfs2 updates
- kernel/watchdog feature
- about half of mm/
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (122 commits)
Documentation: update arch list in the 'memtest' entry
Kconfig: memtest: update number of test patterns up to 17
arm: add support for memtest
arm64: add support for memtest
memtest: use phys_addr_t for physical addresses
mm: move memtest under mm
mm, hugetlb: abort __get_user_pages if current has been oom killed
mm, mempool: do not allow atomic resizing
memcg: print cgroup information when system panics due to panic_on_oom
mm: numa: remove migrate_ratelimited
mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
mm: split ET_DYN ASLR from mmap ASLR
s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE
mm: expose arch_mmap_rnd when available
s390: standardize mmap_rnd() usage
powerpc: standardize mmap_rnd() usage
mips: extract logic for mmap_rnd()
arm64: standardize mmap_rnd() usage
x86: standardize mmap_rnd() usage
arm: factor out mmap ASLR into mmap_rnd
...
Diffstat (limited to 'Documentation/cma')
-rw-r--r-- | Documentation/cma/debugfs.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/cma/debugfs.txt b/Documentation/cma/debugfs.txt new file mode 100644 index 0000000..6cef20a --- /dev/null +++ b/Documentation/cma/debugfs.txt @@ -0,0 +1,21 @@ +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. |