hugetlb: add MAP_HUGETLB example
Add an example of how to use the MAP_HUGETLB flag to the vm documentation
directory and a reference to the example in hugetlbpage.txt.
Signed-off-by: Eric B Munson <ebmunson@us.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/vm/hugetlbpage.txt b/Documentation/vm/hugetlbpage.txt
index 3a167be7..82a7bd1 100644
--- a/Documentation/vm/hugetlbpage.txt
+++ b/Documentation/vm/hugetlbpage.txt
@@ -187,12 +187,14 @@
used to change the file attributes on hugetlbfs.
Also, it is important to note that no such mount command is required if the
-applications are going to use only shmat/shmget system calls. Users who
-wish to use hugetlb page via shared memory segment should be a member of
-a supplementary group and system admin needs to configure that gid into
-/proc/sys/vm/hugetlb_shm_group. It is possible for same or different
-applications to use any combination of mmaps and shm* calls, though the
-mount of filesystem will be required for using mmap calls.
+applications are going to use only shmat/shmget system calls or mmap with
+MAP_HUGETLB. Users who wish to use hugetlb page via shared memory segment
+should be a member of a supplementary group and system admin needs to
+configure that gid into /proc/sys/vm/hugetlb_shm_group. It is possible for
+same or different applications to use any combination of mmaps and shm*
+calls, though the mount of filesystem will be required for using mmap calls
+without MAP_HUGETLB. For an example of how to use mmap with MAP_HUGETLB see
+map_hugetlb.c.
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