From eed415727208bd8921813ea45b893c88208af443 Mon Sep 17 00:00:00 2001
From: Jeff Squyres <jsquyres@cisco.com>
Date: Wed, 20 Jan 2021 07:10:15 -0800
Subject: [PATCH 1/2] MPI_Init_thread(3): update refs about MPI_THREAD_MULTIPLE
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Thanks to Andreas Lösel for bringing the outdated docs to our
attention.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
(cherry picked from commit 0a52936a6f6539e45835a1907f1192175e658484)
---
 ompi/mpi/man/man3/MPI_Init_thread.3in | 46 +++++++--------------------
 1 file changed, 11 insertions(+), 35 deletions(-)

diff --git a/ompi/mpi/man/man3/MPI_Init_thread.3in b/ompi/mpi/man/man3/MPI_Init_thread.3in
index 7afe8cc1658..4205dbcd40f 100644
--- a/ompi/mpi/man/man3/MPI_Init_thread.3in
+++ b/ompi/mpi/man/man3/MPI_Init_thread.3in
@@ -1,7 +1,8 @@
 .\" -*- nroff -*-
 .\" Copyright 2006-2008 Sun Microsystems, Inc.
 .\" Copyright (c) 1996 Thinking Machines Corporation
-.\" Copyright (c) 2010-2015 Cisco Systems, Inc.  All rights reserved.
+.\" Copyright (c) 2010-2020 Cisco Systems, Inc.  All rights reserved.
+.\" Copyright (c) 2020      Google, LLC. All rights reserved.
 .\" $COPYRIGHT$
 .TH MPI_Init_thread 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
 .
@@ -135,52 +136,27 @@ opening files, reading standard input, or writing to standard output.
 .
 .SH MPI_THREAD_MULTIPLE Support
 .
-MPI_THREAD_MULTIPLE support is included if Open MPI was configured
-with the --enable-mpi-thread-multiple configure switch.  You can check the
+MPI_THREAD_MULTIPLE support is included if the environment in which
+Open MPI was built supports threading.  You can check the
 output of
 .BR ompi_info (1)
 to see if Open MPI has MPI_THREAD_MULTIPLE support:
 .
 .PP
 .nf
-shell$ ompi_info | grep -i thread
-          Thread support: posix (mpi: yes, progress: no)
+shell$ ompi_info | grep "Thread support"
+          Thread support: posix (MPI_THREAD_MULTIPLE: yes, OPAL support: yes, OMPI progress: no, Event lib: yes)
 shell$
 .fi
 .
 .PP
-The "mpi: yes" portion of the above output indicates that Open MPI was
-compiled with MPI_THREAD_MULTIPLE support.
+The "MPI_THREAD_MULTIPLE: yes" portion of the above output indicates
+that Open MPI was compiled with MPI_THREAD_MULTIPLE support.
 .
 .PP
-Note that MPI_THREAD_MULTIPLE support is only lightly tested.  It
-likely does not work for thread-intensive applications.  Also note
-that
-.I only
-the MPI point-to-point communication functions for the BTL's listed
-below are considered thread safe.  Other support functions (e.g., MPI
-attributes) have not been certified as safe when simultaneously used
-by multiple threads.
-.
-.PP
-.nf
-    tcp
-    sm
-    mx
-    elan
-    self
-.fi
-.
-.PP
-Note that Open MPI's thread support is in a fairly early stage; the
-above devices are likely to
-.IR work ,
-but the latency is likely to be fairly high.  Specifically, efforts so
-far have concentrated on
-.IR correctness ,
-not
-.I performance
-(yet).
+Note that there is a small performance penalty for using
+MPI_THREAD_MULTIPLE support; latencies for short messages will be
+higher as compared to when using MPI_THREAD_SINGLE, for example.
 .
 .
 .SH ERRORS

From 1abbeddf7bcdb4190ea423a3e61cd33fe21562d4 Mon Sep 17 00:00:00 2001
From: Jeff Squyres <jsquyres@cisco.com>
Date: Wed, 20 Jan 2021 07:15:05 -0800
Subject: [PATCH 2/2] MPI_Init_thread(3): fix statement about C++ binding
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Thanks to Andreas Lösel for raising the inaccurate statement to our
attention.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
(cherry picked from commit 28508eb9277a4bac4eec7c087417726461739d83)
---
 ompi/mpi/man/man3/MPI_Init_thread.3in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ompi/mpi/man/man3/MPI_Init_thread.3in b/ompi/mpi/man/man3/MPI_Init_thread.3in
index 4205dbcd40f..a3c7d5a0915 100644
--- a/ompi/mpi/man/man3/MPI_Init_thread.3in
+++ b/ompi/mpi/man/man3/MPI_Init_thread.3in
@@ -93,7 +93,7 @@ with no restrictions.
 .
 .PP
 The level of thread support available to the program is set in
-\fIprovided\fP, except in C++, where it is the return value of the
+\fIprovided\fP, except in the C++ binding, where it is the return value of the
 function. In Open MPI, the value is dependent on how the library was
 configured and built. Note that there is no guarantee that
 \fIprovided\fP will be greater than or equal to \fIrequired\fP.