Messages in this thread Patch in this message | | | Date | Tue, 21 Jul 2015 17:41:34 -0700 (PDT) | From | David Rientjes <> | Subject | [patch] mmap.2: document the munmap exception for underlying page size |
| |
munmap(2) will fail with an errno of EINVAL for hugetlb memory if the length is not a multiple of the underlying page size.
Documentation/vm/hugetlbpage.txt was updated to specify this behavior since Linux 4.1 in commit 80d6b94bd69a ("mm, doc: cleanup and clarify munmap behavior for hugetlb memory").
Signed-off-by: David Rientjes <rientjes@google.com> --- man2/mmap.2 | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/man2/mmap.2 b/man2/mmap.2 --- a/man2/mmap.2 +++ b/man2/mmap.2 @@ -383,6 +383,10 @@ All pages containing a part of the indicated range are unmapped, and subsequent references to these pages will generate .BR SIGSEGV . +An exception is when the underlying memory is not of the native page +size, such as hugetlb page sizes, whereas +.I length +must be a multiple of the underlying page size. It is not an error if the indicated range does not contain any mapped pages. .SS Timestamps changes for file-backed mappings
| |