diff options
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/nommu-mmap.txt | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/Documentation/nommu-mmap.txt b/Documentation/nommu-mmap.txt index 7714f57caad5..02b89dcf38ac 100644 --- a/Documentation/nommu-mmap.txt +++ b/Documentation/nommu-mmap.txt | |||
@@ -109,12 +109,18 @@ and it's also much more restricted in the latter case: | |||
109 | FURTHER NOTES ON NO-MMU MMAP | 109 | FURTHER NOTES ON NO-MMU MMAP |
110 | ============================ | 110 | ============================ |
111 | 111 | ||
112 | (*) A request for a private mapping of less than a page in size may not return | 112 | (*) A request for a private mapping of a file may return a buffer that is not |
113 | a page-aligned buffer. This is because the kernel calls kmalloc() to | 113 | page-aligned. This is because XIP may take place, and the data may not be |
114 | allocate the buffer, not get_free_page(). | 114 | paged aligned in the backing store. |
115 | 115 | ||
116 | (*) A list of all the mappings on the system is visible through /proc/maps in | 116 | (*) A request for an anonymous mapping will always be page aligned. If |
117 | no-MMU mode. | 117 | possible the size of the request should be a power of two otherwise some |
118 | of the space may be wasted as the kernel must allocate a power-of-2 | ||
119 | granule but will only discard the excess if appropriately configured as | ||
120 | this has an effect on fragmentation. | ||
121 | |||
122 | (*) A list of all the private copy and anonymous mappings on the system is | ||
123 | visible through /proc/maps in no-MMU mode. | ||
118 | 124 | ||
119 | (*) A list of all the mappings in use by a process is visible through | 125 | (*) A list of all the mappings in use by a process is visible through |
120 | /proc/<pid>/maps in no-MMU mode. | 126 | /proc/<pid>/maps in no-MMU mode. |