In preparation for discussing newly introduced mremap() behaviour to permit
the move of multiple mappings at once, add a section to the mremap.2 man
page to describe these operations in general.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
 man/man2/mremap.2 | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/man/man2/mremap.2 b/man/man2/mremap.2
index 2168ca728..4e3c8e54e 100644
--- a/man/man2/mremap.2
+++ b/man/man2/mremap.2
@@ -25,6 +25,20 @@ moving it at the same time (controlled by the
 argument and
 the available virtual address space).
 .P
+Mappings can also simply be moved
+(without any resizing)
+by specifying equal
+.I old_size
+and
+.I new_size
+and using the
+.B MREMAP_FIXED
+flag
+(see below).
+The
+.B MREMAP_DONTUNMAP
+flag may also be specified.
+.P
 .I old_address
 is the old address of the virtual memory block that you
 want to expand (or shrink).
-- 
2.50.1