From 64299ceae3d8eee047fe34dc22f82477de2ed13d Mon Sep 17 00:00:00 2001
From: Joshua Hursey <jhursey@us.ibm.com>
Date: Thu, 1 Sep 2022 13:58:05 -0400
Subject: [PATCH] Make stream buffing an MCA option again

 * Way back when the stream buffering option was introduced
   it was an MCA: https://github.com/open-mpi/ompi/commit/4dd9f89a9
   - It changed to a CLI option at some point.
 * Make this an MCA option once again, and connect it with the
   PRRTE CLI options.

Signed-off-by: Joshua Hursey <jhursey@us.ibm.com>
(cherry picked from commit 3a8edb7a135ef77fda509b7af78536a4e4e14b60)
---
 ompi/runtime/ompi_mpi_params.c | 30 ++++++++++++++++++++++++++++++
 ompi/runtime/ompi_rte.c        | 20 --------------------
 2 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/ompi/runtime/ompi_mpi_params.c b/ompi/runtime/ompi_mpi_params.c
index 10f0bf00ab6..b7409b63e3f 100644
--- a/ompi/runtime/ompi_mpi_params.c
+++ b/ompi/runtime/ompi_mpi_params.c
@@ -23,6 +23,7 @@
  * Copyright (c) 2018-2021 Triad National Security, LLC. All rights
  *                         reserved.
  * Copyright (c) 2021      Nanook Consulting.  All rights reserved.
+ * Copyright (c) 2022      IBM Corporation.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -102,6 +103,8 @@ bool ompi_ftmpi_enabled = false;
 #include "ompi/communicator/communicator.h"
 #endif /* OPAL_ENABLE_FT_MPI */
 
+static int ompi_stream_buffering_mode = -1;
+
 int ompi_mpi_register_params(void)
 {
     int value;
@@ -404,6 +407,33 @@ int ompi_mpi_register_params(void)
                                  MCA_BASE_VAR_SCOPE_READONLY,
                                  &ompi_enable_timing);
 
+    /*
+     * stdout/stderr buffering
+     * If the user requested to override the default setting then do
+     * as they wish.
+     */
+    (void) mca_base_var_register("ompi", "ompi", NULL, "stream_buffering",
+                                 "Adjust buffering for stdout/stderr. "
+                                 "(0) unbuffered, (1) line buffered, (2) fully buffered.",
+                                 MCA_BASE_VAR_TYPE_INT,
+                                 NULL, 0, 0,
+                                 OPAL_INFO_LVL_3,
+                                 MCA_BASE_VAR_SCOPE_READONLY,
+                                 &ompi_stream_buffering_mode);
+    if(0 == ompi_stream_buffering_mode) {
+        setvbuf(stdout, NULL, _IONBF, 0);
+        setvbuf(stderr, NULL, _IONBF, 0);
+    }
+    else if(1 == ompi_stream_buffering_mode) {
+        setvbuf(stdout, NULL, _IOLBF, 0);
+        setvbuf(stderr, NULL, _IOLBF, 0);
+    }
+    else if(2 == ompi_stream_buffering_mode) {
+        setvbuf(stdout, NULL, _IOFBF, 0);
+        setvbuf(stderr, NULL, _IOFBF, 0);
+    }
+
+
 #if OPAL_ENABLE_FT_MPI
     /* Before loading any other part of the MPI library, we need to load
  *      * the ft-mpi tune file to override default component selection when
diff --git a/ompi/runtime/ompi_rte.c b/ompi/runtime/ompi_rte.c
index 6071b9bf65f..667dafb15a3 100644
--- a/ompi/runtime/ompi_rte.c
+++ b/ompi/runtime/ompi_rte.c
@@ -900,26 +900,6 @@ int ompi_rte_init(int *pargc, char ***pargv)
         opal_argv_free(peers);
     }
 
-    /*
-     * stdout/stderr buffering
-     * If the user requested to override the default setting then do
-     * as they wish.
-     */
-    OPAL_MODEX_RECV_VALUE_OPTIONAL(rc, "OMPI_STREAM_BUFFERING",
-                                   &opal_process_info.my_name, &u16ptr, PMIX_UINT16);
-    if (PMIX_SUCCESS == rc) {
-        if (0 == u16) {
-            setvbuf(stdout, NULL, _IONBF, 0);
-            setvbuf(stderr, NULL, _IONBF, 0);
-        } else if (1 == u16) {
-            setvbuf(stdout, NULL, _IOLBF, 0);
-            setvbuf(stderr, NULL, _IOLBF, 0);
-        } else if (2 == u16 ) {
-            setvbuf(stdout, NULL, _IOFBF, 0);
-            setvbuf(stderr, NULL, _IOFBF, 0);
-        }
-    }
-
 #ifdef PMIX_NODE_OVERSUBSCRIBED
     pname.jobid = opal_process_info.my_name.jobid;
     pname.vpid = OPAL_VPID_WILDCARD;