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Diffstat (limited to 'Documentation/nommu-mmap.txt')
| -rw-r--r-- | Documentation/nommu-mmap.txt | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/nommu-mmap.txt b/Documentation/nommu-mmap.txt index 83f4b083d57e..3ce890664936 100644 --- a/Documentation/nommu-mmap.txt +++ b/Documentation/nommu-mmap.txt @@ -128,6 +128,30 @@ FURTHER NOTES ON NO-MMU MMAP error will result if they don't. This is most likely to be encountered with character device files, pipes, fifos and sockets. + +============= +NO-MMU MREMAP +============= + +The mremap() function is partially supported. It may change the size of a +mapping, and may move it[*] if MREMAP_MAYMOVE is specified and if the new size +of the mapping exceeds the size of the slab object currently occupied by the +memory to which the mapping refers, or if a smaller slab object could be used. + +MREMAP_FIXED is not supported, though it is ignored if there's no change of +address and the object does not need to be moved. + +Shared mappings may not be moved. Shareable mappings may not be moved either, +even if they are not currently shared. + +The mremap() function must be given an exact match for base address and size of +a previously mapped object. It may not be used to create holes in existing +mappings, move parts of existing mappings or resize parts of mappings. It must +act on a complete mapping. + +[*] Not currently supported. + + ============================================ PROVIDING SHAREABLE CHARACTER DEVICE SUPPORT ============================================ |