[src/trunk]: src/share/man/man9 mention memory barriers necessary for non-int...

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/14c82f706da1
branches:  trunk
changeset: 765670:14c82f706da1
user:      yamt <yamt%NetBSD.org@localhost>
date:      Thu Jun 02 00:58:26 2011 +0000

description:
mention memory barriers necessary for non-interlocked adaptive mutex release.

diffstat:

 share/man/man9/cpu_switchto.9 |  11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diffs (38 lines):

diff -r 9790606a008f -r 14c82f706da1 share/man/man9/cpu_switchto.9
--- a/share/man/man9/cpu_switchto.9     Thu Jun 02 00:35:23 2011 +0000
+++ b/share/man/man9/cpu_switchto.9     Thu Jun 02 00:58:26 2011 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: cpu_switchto.9,v 1.11 2010/04/13 06:05:56 jruoho Exp $
+.\"    $NetBSD: cpu_switchto.9,v 1.12 2011/06/02 00:58:26 yamt Exp $
 .\"
 .\" Copyright (c)2007 YAMAMOTO Takashi,
 .\" All rights reserved.
@@ -25,7 +25,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\" ------------------------------------------------------------
-.Dd April 13, 2010
+.Dd June 2, 2011
 .Dt CPU_SWITCHTO 9
 .Os
 .\" ------------------------------------------------------------
@@ -64,6 +64,12 @@
 .Xr curlwp 9
 to
 .Fa newlwp .
+If the architecture does non-interlocked adaptive mutex release,
+.Fn cpu_switchto
+does an equivalent of
+.Xr membar_producer 9 ,
+before and after the modification of
+.Xr curlwp 9 .
 .It
 .Fn cpu_switchto
 should be called at
@@ -138,5 +144,6 @@
 .Sh SEE ALSO
 .Xr swapcontext 3 ,
 .Xr intro 9 ,
+.Xr membar_producer 9 ,
 .Xr mutex 9 ,
 .Xr spl 9