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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 commit is cherry-picked off a fix that was submitted for the v1.8 release series but never applied to master. This fixes part of the problem reported by @nysal in open-mpi#1902. (cherry picked from commit open-mpi/ompi-release@ce91307) Signed-off-by: Nathan Hjelm <hjelmn@me.com>
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| /* -*- 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 | ||
| * Corporation. All rights reserved. | ||
| * Copyright (c) 2004-2007 The University of Tennessee and The University | ||
| * of Tennessee Research Foundation. All rights | ||
| * reserved. | ||
| * Copyright (c) 2004-2006 High Performance Computing Center Stuttgart, | ||
| * University of Stuttgart. All rights reserved. | ||
| * 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) 2015-2016 Los Alamos National Security, LLC. All rights | ||
| * reserved. | ||
| * $COPYRIGHT$ | ||
| * | ||
| * Additional copyrights may follow | ||
| * | ||
| * $HEADER$ | ||
| */ | ||
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| #if !defined(OPAL_THREAD_USAGE_H) | ||
| #define OPAL_THREAD_USAGE_H | ||
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| #include "opal_config.h" | ||
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| #include "opal/sys/atomic.h" | ||
| #include "opal/prefetch.h" | ||
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| OPAL_DECLSPEC extern bool opal_uses_threads; | ||
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| /** | ||
| * 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 | ||
| * | ||
| * 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 MPI_INIT is invoked, and the ompi components in use are | ||
| * 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. | ||
| */ | ||
| #define opal_using_threads() opal_uses_threads | ||
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| /** | ||
| * 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) | ||
| { | ||
| opal_uses_threads = have; | ||
| return opal_using_threads(); | ||
| } | ||
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| /** | ||
| * Use an atomic operation for increment/decrement if opal_using_threads() | ||
| * indicates that threads are in use by the application or library. | ||
| */ | ||
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| static inline int32_t | ||
| OPAL_THREAD_ADD32(volatile int32_t *addr, int delta) | ||
| { | ||
| int32_t ret; | ||
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| if (OPAL_UNLIKELY(opal_using_threads())) { | ||
| ret = opal_atomic_add_32(addr, delta); | ||
| } else { | ||
| ret = (*addr += delta); | ||
| } | ||
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| return ret; | ||
| } | ||
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| #if OPAL_HAVE_ATOMIC_MATH_64 | ||
| static inline int64_t | ||
| OPAL_THREAD_ADD64(volatile int64_t *addr, int delta) | ||
| { | ||
| int64_t ret; | ||
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| if (OPAL_UNLIKELY(opal_using_threads())) { | ||
| ret = opal_atomic_add_64(addr, delta); | ||
| } else { | ||
| ret = (*addr += delta); | ||
| } | ||
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| return ret; | ||
| } | ||
| #endif | ||
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| static inline size_t | ||
| OPAL_THREAD_ADD_SIZE_T(volatile size_t *addr, int delta) | ||
| { | ||
| size_t ret; | ||
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| if (OPAL_UNLIKELY(opal_using_threads())) { | ||
| ret = opal_atomic_add_size_t(addr, delta); | ||
| } else { | ||
| ret = (*addr += delta); | ||
| } | ||
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| return ret; | ||
| } | ||
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| /* BWB: FIX ME: remove if possible */ | ||
| #define OPAL_CMPSET(x, y, z) ((*(x) == (y)) ? ((*(x) = (z)), 1) : 0) | ||
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| #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 | ||
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| static inline void *opal_thread_swap_ptr (volatile void *ptr, void *newvalue) | ||
| { | ||
| if (opal_using_threads ()) { | ||
| return opal_atomic_swap_ptr (ptr, newvalue); | ||
| } | ||
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| void *old = ((void **) ptr)[0]; | ||
| ((void **) ptr)[0] = newvalue; | ||
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| return old; | ||
| } | ||
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| #define OPAL_ATOMIC_SWAP_PTR(x, y) opal_thread_swap_ptr (x, y) | ||
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| #endif /* !defined(OPAL_THREAD_USAGE_H) */ |