btl/vader: rename vader -> sm

Now that the old sm btl has been gone for some time there was a request
to rename vader to sm. This commit does just that (reluctantly).

An alias has been generated so specifying vader in the btl selection
variable or specifying vader parameters will continue to work.

Signed-off-by: Nathan Hjelm <hjelmn@google.com>

Author: hjelmn

README

@@ -594,7 +594,6 @@ MPI Functionality and Features
       - tcp
       - ugni
       - usnic
-      - vader (shared memory)
 
   Currently, MPI File operations are not thread safe even if MPI is
   initialized for MPI_THREAD_MULTIPLE support.
@@ -675,8 +674,8 @@ Network Support
     - SMCUDA
     - Cisco usNIC
     - uGNI (Cray Gemini, Aries)
-    - vader (XPMEM, Linux CMA, Linux KNEM, and copy-in/copy-out shared
-      memory)
+    - shared memory (XPMEM, Linux CMA, Linux KNEM, and
+      copy-in/copy-out shared memory)
 
   - "cm" supports a smaller number of networks (and they cannot be
     used together), but may provide better overall MPI performance:
@@ -785,16 +784,16 @@ Network Support
   v2.6.15 with libibverbs v1.1 or later (first released as part of
   OFED v1.2), per restrictions imposed by the OFED network stack.
 
-- Linux "knem" support is used when the "vader" or "sm" (shared
-  memory) BTLs are compiled with knem support (see the --with-knem
-  configure option) and the knem Linux module is loaded in the running
-  kernel.  If the knem Linux kernel module is not loaded, the knem
-  support is (by default) silently deactivated during Open MPI jobs.
+- Linux "knem" support is used when the "sm" (shared memory) BTL is
+  compiled with knem support (see the --with-knem configure option)
+  and the knem Linux module is loaded in the running kernel.  If the
+  knem Linux kernel module is not loaded, the knem support is (by
+  default) silently deactivated during Open MPI jobs.
 
   See https://knem.gforge.inria.fr/ for details on Knem.
 
-- Linux Cross-Memory Attach (CMA) or XPMEM is used by the vader
-  shared-memory BTL when the CMA/XPMEM libraries are installedm,
+- Linux Cross-Memory Attach (CMA) or XPMEM is used by the "sm" shared
+  memory BTL when the CMA/XPMEM libraries are installedm,
   respectively.  Linux CMA and XPMEM are similar (but different)
   mechanisms for Open MPI to utilize single-copy semantics for shared
   memory.
@@ -2154,14 +2153,14 @@ comma-delimited list to the "btl" MCA parameter:
 
    shell$ mpirun --mca btl tcp,self hello_world_mpi
 
-To add shared memory support, add "vader" into the command-delimited
-list (list order does not matter):
+To add shared memory support, add "sm" into the command-delimited list
+(list order does not matter):
 
-   shell$ mpirun --mca btl tcp,vader,self hello_world_mpi
+   shell$ mpirun --mca btl tcp,sm,self hello_world_mpi
 
-(there is an "sm" shared memory BTL, too, but "vader" is a newer
-generation of shared memory support; by default, "vader" will be used
-instead of "sm")
+(there used to be a "vader" BTL for shared memory support; it was
+renamed to "sm" in Open MPI v5.0.0, but the alias "vader" still works
+as well)
 
 To specifically deactivate a specific component, the comma-delimited
 list can be prepended with a "^" to negate it:

opal/mca/btl/base/btl_base_frame.c

@@ -16,6 +16,7 @@
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2016-2018 Los Alamos National Security, LLC. All rights
  *                         reserved.
+ * Copyright (c) 2020      Google, LLC. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -30,6 +31,7 @@
 #include "opal/mca/mca.h"
 #include "opal/util/output.h"
 #include "opal/mca/base/base.h"
+#include "opal/mca/base/mca_base_alias.h"
 #include "opal/mca/btl/btl.h"
 #include "opal/mca/btl/base/base.h"
 
@@ -154,6 +156,29 @@ static int mca_btl_base_register(mca_base_register_flag_t flags)
     (void) mca_base_var_enum_register("opal", "btl", "base", "btl_atomic_flags",
                                  &mca_btl_base_atomic_enum);
 
+    /* Note that we break abstraction rules here by listing two
+       specific BTLs here in the base.  This is necessary, however,
+       due to extraordinary circumstances:
+
+       1. In Open MPI v5.0.0, we want to rename the "vader" BTL to be
+          "sm", because the "old" sm BTL is long gone, and the "vader"
+          name is not very user-friendly.
+
+       2. The MCA aliasing mechanism was therefore created for v5.0.0.
+          Both the component itself and all of its MCA vars are
+          aliased.
+
+       3. However -- at least as currently implemented -- by the time
+          individual components are registered, it's too late to make
+          aliases.  Hence, if we want to preserve the name "vader" for
+          some sembalance of backwards compatibility (and we do!), we
+          have to register "vader" as an "alias for "sm" up here in
+          the BTL base, before any BTL components are registered.
+
+       This is why we tolerate this abstraction break up here in the
+       BTL component base. */
+    (void) mca_base_alias_register ("opal", "btl", "sm", "vader", MCA_BASE_ALIAS_FLAG_NONE);
+
     return OPAL_SUCCESS;
 }
 

opal/mca/btl/btl.h

@@ -18,6 +18,7 @@
  * Copyright (c) 2015      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2020      Intel, Inc.  All rights reserved.
+ * Copyright (c) 2020      Google, LLC. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -190,7 +191,7 @@ typedef uint8_t mca_btl_base_tag_t;
 #define MCA_BTL_TAG_IB                (MCA_BTL_TAG_BTL + 0)
 #define MCA_BTL_TAG_UDAPL             (MCA_BTL_TAG_BTL + 1)
 #define MCA_BTL_TAG_SMCUDA            (MCA_BTL_TAG_BTL + 2)
-#define MCA_BTL_TAG_VADER             (MCA_BTL_TAG_BTL + 3)
+#define MCA_BTL_TAG_SM                (MCA_BTL_TAG_BTL + 3)
 
 /* prefered protocol */
 #define MCA_BTL_FLAGS_SEND            0x0001

opal/mca/btl/vader/Makefile.am renamed to opal/mca/btl/sm/Makefile.am

@@ -13,57 +13,58 @@
 # Copyright (c) 2011-2014 Los Alamos National Security, LLC. All rights
 #                         reserved.
 # Copyright (c) 2017      IBM Corporation.  All rights reserved.
+# Copyright (c) 2020      Google, LLC. All rights reserved.
 # $COPYRIGHT$
 #
 # Additional copyrights may follow
 #
 # $HEADER$
 #
 
-AM_CPPFLAGS = $(btl_vader_CPPFLAGS)
+AM_CPPFLAGS = $(btl_sm_CPPFLAGS)
 
-dist_opaldata_DATA = help-btl-vader.txt
+dist_opaldata_DATA = help-btl-sm.txt
 
-libmca_btl_vader_la_sources = \
-    btl_vader_module.c \
-    btl_vader.h \
-    btl_vader_component.c \
-    btl_vader_endpoint.h \
-    btl_vader_fifo.h \
-    btl_vader_frag.c \
-    btl_vader_frag.h \
-    btl_vader_send.c \
-    btl_vader_sendi.c \
-    btl_vader_fbox.h \
-    btl_vader_get.c \
-    btl_vader_put.c \
-    btl_vader_xpmem.c \
-    btl_vader_xpmem.h \
-    btl_vader_knem.c \
-    btl_vader_knem.h \
-    btl_vader_sc_emu.c \
-    btl_vader_atomic.c
+libmca_btl_sm_la_sources = \
+    btl_sm_module.c \
+    btl_sm.h \
+    btl_sm_component.c \
+    btl_sm_endpoint.h \
+    btl_sm_fifo.h \
+    btl_sm_frag.c \
+    btl_sm_frag.h \
+    btl_sm_send.c \
+    btl_sm_sendi.c \
+    btl_sm_fbox.h \
+    btl_sm_get.c \
+    btl_sm_put.c \
+    btl_sm_xpmem.c \
+    btl_sm_xpmem.h \
+    btl_sm_knem.c \
+    btl_sm_knem.h \
+    btl_sm_sc_emu.c \
+    btl_sm_atomic.c
 
 # Make the output library in this directory, and name it either
 # mca_<type>_<name>.la (for DSO builds) or libmca_<type>_<name>.la
 # (for static builds).
 
-if MCA_BUILD_opal_btl_vader_DSO
+if MCA_BUILD_opal_btl_sm_DSO
 component_noinst =
-component_install = mca_btl_vader.la
+component_install = mca_btl_sm.la
 else
-component_noinst = libmca_btl_vader.la
+component_noinst = libmca_btl_sm.la
 component_install =
 endif
 
 mcacomponentdir = $(opallibdir)
 mcacomponent_LTLIBRARIES = $(component_install)
-mca_btl_vader_la_SOURCES = $(libmca_btl_vader_la_sources)
-mca_btl_vader_la_LDFLAGS = -module -avoid-version $(btl_vader_LDFLAGS)
-mca_btl_vader_la_LIBADD = $(top_builddir)/opal/lib@OPAL_LIB_PREFIX@open-pal.la \
-	$(btl_vader_LIBS)
+mca_btl_sm_la_SOURCES = $(libmca_btl_sm_la_sources)
+mca_btl_sm_la_LDFLAGS = -module -avoid-version $(btl_sm_LDFLAGS)
+mca_btl_sm_la_LIBADD = $(top_builddir)/opal/lib@OPAL_LIB_PREFIX@open-pal.la \
+	$(btl_sm_LIBS)
 
 noinst_LTLIBRARIES = $(component_noinst)
-libmca_btl_vader_la_SOURCES = $(libmca_btl_vader_la_sources)
-libmca_btl_vader_la_LIBADD = $(btl_vader_LIBS)
-libmca_btl_vader_la_LDFLAGS = -module -avoid-version $(btl_vader_LDFLAGS)
+libmca_btl_sm_la_SOURCES = $(libmca_btl_sm_la_sources)
+libmca_btl_sm_la_LIBADD = $(btl_sm_LIBS)
+libmca_btl_sm_la_LDFLAGS = -module -avoid-version $(btl_sm_LDFLAGS)