Fix performance regression caused by enabling opal thread support

This commit adds opal_using_threads() protection around the atomic
operation in OBJ_RETAIN/OBJ_RELEASE. This resolves the performance
issues seen when running psm with MPI_THREAD_SINGLE.

To avoid issues with header dependencies opal_using_threads() has been
moved to a new header (thread_usage.h). The OPAL_THREAD_ADD* and
OPAL_THREAD_CMPSET* macros have also been relocated to this header.

This was cherry-picked off a fix applied to v1.8 and not master. See
open-mpi/ompi#1902.

(cherry picked from commit ce91307)

Signed-off-by: Nathan Hjelm <[email protected]>

Author: hjelmn

opal/class/opal_object.h

@@ -1,3 +1,4 @@
+/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
 /*
  * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
  *                         University Research and Technology
@@ -10,6 +11,10 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007-2014 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2014      Research Organization for Information Science
+ *                         and Technology (RIST). All rights reserved.
+ * Copyright (c) 2015      Los Alamos National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -120,7 +125,7 @@
 #include <assert.h>
 #include <stdlib.h>
 
-#include "opal/sys/atomic.h"
+#include "opal/threads/thread_usage.h"
 
 BEGIN_C_DECLS
 
@@ -503,7 +508,7 @@ static inline opal_object_t *opal_obj_new(opal_class_t * cls)
 static inline int opal_obj_update(opal_object_t *object, int inc) __opal_attribute_always_inline__;
 static inline int opal_obj_update(opal_object_t *object, int inc)
 {
-    return opal_atomic_add_32(&(object->obj_reference_count), inc);
+    return OPAL_THREAD_ADD32(&object->obj_reference_count, inc);
 }
 
 END_C_DECLS

opal/threads/Makefile.am

@@ -29,7 +29,8 @@ headers += \
         threads/mutex_unix.h \
         threads/threads.h \
         threads/tsd.h \
-        threads/wait_sync.h
+        threads/wait_sync.h \
+	threads/thread_usage.h
 
 lib@OPAL_LIB_PREFIX@open_pal_la_SOURCES += \
         threads/condition.c \

opal/threads/mutex.h

@@ -28,7 +28,7 @@
 
 #include "opal_config.h"
 
-#include "opal/sys/atomic.h"
+#include "opal/threads/thread_usage.h"
 
 BEGIN_C_DECLS
 
@@ -40,13 +40,6 @@ BEGIN_C_DECLS
  * Functions for locking of critical sections.
  */
 
-#if OMPI_ENABLE_THREAD_MULTIPLE
-/*
- * declaring this here so that CL does not complain
- */
-OPAL_DECLSPEC extern bool opal_uses_threads;
-#endif
-
 /**
  * Opaque mutex object
  */
@@ -108,73 +101,6 @@ END_C_DECLS
 
 BEGIN_C_DECLS
 
-/**
- * Check and see if the process is using multiple threads.
- *
- * @retval true If the process may have more than one thread.
- * @retval false If the process only has a single thread.
- *
- * The value that this function returns is influenced by:
- *
- * - how MPI_INIT or MPI_INIT_THREAD was invoked,
- * - what the final MPI thread level was determined to be,
- * - whether the OMPI or MPI libraries are multi-threaded (Jan 2003:
- *   they're not),
- * - whether configure determined if we have thread support or not
- *
- * MPI_INIT and MPI_INIT_THREAD (specifically, back-end OMPI startup
- * functions) invoke opal_set_using_threads() to influence the value of
- * this function, depending on their situation. Some examples:
- *
- * - if configure determined that we do not have threads, then this
- * value will always be false.
- *
- * - if MPI_INIT is invoked, and the ompi libraries are [still]
- * single-threaded, this value will be false.
- *
- * - if MPI_INIT_THREAD is invoked with MPI_THREAD_MULTIPLE, we have
- * thread support, and the final thread level is determined to be
- * MPI_THREAD_MULTIPLE, this value will be true.
- *
- * - if the process is a single-threaded OMPI executable (e.g., mpicc),
- * this value will be false.
- *
- * Hence, this function will return false if there is guaranteed to
- * only be one thread in the process.  If there is even the
- * possibility that we may have multiple threads, true will be
- * returned.
- */
-#if OMPI_ENABLE_THREAD_MULTIPLE
-#define opal_using_threads()  opal_uses_threads
-#else
-#define opal_using_threads()  0
-#endif
-
-/**
- * Set whether the process is using multiple threads or not.
- *
- * @param have Boolean indicating whether the process is using
- * multiple threads or not.
- *
- * @retval opal_using_threads The new return value from
- * opal_using_threads().
- *
- * This function is used to influence the return value of
- * opal_using_threads().  If configure detected that we have thread
- * support, the return value of future invocations of
- * opal_using_threads() will be the parameter's value.  If configure
- * detected that we have no thread support, then the retuen from
- * opal_using_threads() will always be false.
- */
-static inline bool opal_set_using_threads(bool have)
-{
-#if OMPI_ENABLE_THREAD_MULTIPLE
-    opal_uses_threads = have;
-#endif
-    return opal_using_threads();
-}
-
-
 /**
  * Lock a mutex if opal_using_threads() says that multiple threads may
  * be active in the process.
@@ -261,90 +187,6 @@ static inline bool opal_set_using_threads(bool have)
         }                                       \
     } while (0)
 
-/**
- * Use an atomic operation for increment/decrement if opal_using_threads()
- * indicates that threads are in use by the application or library.
- */
-
-static inline int32_t
-OPAL_THREAD_ADD32(volatile int32_t *addr, int delta)
-{
-    int32_t ret;
-
-    if (opal_using_threads()) {
-        ret = opal_atomic_add_32(addr, delta);
-    } else {
-        ret = (*addr += delta);
-    }
-
-    return ret;
-}
-
-#if OPAL_HAVE_ATOMIC_MATH_64
-static inline int64_t
-OPAL_THREAD_ADD64(volatile int64_t *addr, int delta)
-{
-    int64_t ret;
-
-    if (opal_using_threads()) {
-        ret = opal_atomic_add_64(addr, delta);
-    } else {
-        ret = (*addr += delta);
-    }
-
-    return ret;
-}
-#endif
-
-static inline size_t
-OPAL_THREAD_ADD_SIZE_T(volatile size_t *addr, int delta)
-{
-    size_t ret;
-
-    if (opal_using_threads()) {
-        ret = opal_atomic_add_size_t(addr, delta);
-    } else {
-        ret = (*addr += delta);
-    }
-
-    return ret;
-}
-
-/* BWB: FIX ME: remove if possible */
-#define OPAL_CMPSET(x, y, z) ((*(x) == (y)) ? ((*(x) = (z)), 1) : 0)
-
-#if OPAL_HAVE_ATOMIC_CMPSET_32
-#define OPAL_ATOMIC_CMPSET_32(x, y, z) \
-    (opal_using_threads() ? opal_atomic_cmpset_32(x, y, z) : OPAL_CMPSET(x, y, z))
-#endif
-#if OPAL_HAVE_ATOMIC_CMPSET_64
-#define OPAL_ATOMIC_CMPSET_64(x, y, z) \
-    (opal_using_threads() ? opal_atomic_cmpset_64(x, y, z) : OPAL_CMPSET(x, y, z))
-#endif
-#if OPAL_HAVE_ATOMIC_CMPSET_32 || OPAL_HAVE_ATOMIC_CMPSET_64
-#define OPAL_ATOMIC_CMPSET(x, y, z) \
-    (opal_using_threads() ? opal_atomic_cmpset(x, y, z) : OPAL_CMPSET(x, y, z))
-#endif
-#if OPAL_HAVE_ATOMIC_CMPSET_32 || OPAL_HAVE_ATOMIC_CMPSET_64
-#define OPAL_ATOMIC_CMPSET_PTR(x, y, z) \
-    (opal_using_threads() ? opal_atomic_cmpset_ptr(x, y, z) : OPAL_CMPSET(x, y, z))
-#endif
-
-
-static inline void *opal_thread_swap_ptr (volatile void *ptr, void *newvalue)
-{
-    if (opal_using_threads ()) {
-        return opal_atomic_swap_ptr (ptr, newvalue);
-    }
-
-    void *old = ((void **) ptr)[0];
-    ((void **) ptr)[0] = newvalue;
-
-    return old;
-}
-
-#define OPAL_ATOMIC_SWAP_PTR(x, y) opal_thread_swap_ptr (x, y)
-
 END_C_DECLS
 
 #endif                          /* OPAL_MUTEX_H */