MFC r303104, r303106:

Update to reflect the fact that pipe() is a wrapper around the pipe2()
system call.

Reviewed by:	jhb, wblock
Sponsored by:	DAPRA, AFRL

Change wording to use function rather than system call in the
description
as well.

Authored by:	zeising
Reviewed by:	brooks

Approved by:	re (gjb)
Sponsored by:	DAPRA, AFRL

1 files changed, 21 insertions, 2 deletions

diff --git a/lib/libc/sys/pipe.2 b/lib/libc/sys/pipe.2
index 4ca7312..63e013a 100644
--- a/lib/libc/sys/pipe.2
+++ b/lib/libc/sys/pipe.2
@@ -28,7 +28,7 @@
 .\"     @(#)pipe.2	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 22, 2016
+.Dd July 20, 2016
 .Dt PIPE 2
 .Os
 .Sh NAME
@@ -46,7 +46,7 @@
 .Sh DESCRIPTION
 The
 .Fn pipe
-system call
+function
 creates a
 .Em pipe ,
 which is an object allowing
@@ -109,6 +109,18 @@ The bidirectional nature of this implementation of pipes is not
 portable to older systems, so it is recommended to use the convention
 for using the endpoints in the traditional manner when using a
 pipe in one direction.
+.Sh IMPLEMENTATION NOTES
+The
+.Fn pipe
+function calls the
+.Fn pipe2
+system call.
+As a result, system call traces such as those captured by
+.Xr dtrace 1
+or
+.Xr ktrace 1
+will show calls to
+.Fn pipe2 .
 .Sh RETURN VALUES
 .Rv -std pipe
 .Sh ERRORS
@@ -157,3 +169,10 @@ The
 .Fn pipe2
 function appeared in
 .Fx 10.0 .
+.Pp
+The
+.Fn pipe
+function became a wrapper around
+.Fn pipe2
+in
+.Fx 11.0 .