1 | /* |
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2 | * sort.c - Parallel sort |
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3 | * |
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4 | * Author Cesar Fuguet Tortolero (2013) |
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5 | * Alain Greiner (2019) |
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6 | * |
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7 | * Copyright (c) UPMC Sorbonne Universites |
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8 | * |
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9 | * This is free software; you can redistribute it and/or modify it |
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10 | * under the terms of the GNU General Public License as published by |
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11 | * the Free Software Foundation; version 2.0 of the License. |
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12 | * |
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13 | * It is distributed in the hope that it will be useful, but |
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14 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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16 | * General Public License for more details. |
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17 | * |
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18 | * You should have received a copy of the GNU General Public License |
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19 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, |
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20 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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21 | */ |
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22 | |
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23 | /////////////////////////////////////////////////////////////////////////////// |
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24 | // This multi-threaded application implement a multi-stage sort. |
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25 | // It has been writen by Cesar Fuget Tortolero in 2013. |
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26 | // It has been ported on ALMOS-MKH by Alain Greiner in 2019. |
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27 | // |
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28 | // There is one thread per physical cores. |
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29 | // Computation is organised as a binary tree: |
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30 | // - All threads execute in parallel a buble sort on a sub-array during the |
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31 | // the first stage of parallel sort, |
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32 | // - The number of participating threads is divided by 2 at each next stage, |
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33 | // to make a merge sort, on two subsets of previous stage. |
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34 | // |
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35 | // Number_of_stages = number of barriers = log2(Number_of_threads) |
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36 | // |
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37 | // The various stages are separated by synchronisation barriers, and the |
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38 | // main thread uses the join syscall to check that all threads completed |
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39 | // before printing the computation time (sequencial & parallel). |
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40 | // These results can be - optionnaly - registered in an instrumentation file. |
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41 | // |
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42 | // Constraints : |
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43 | // - It supports up to 1024 cores: x_size, y_size, and ncores must be |
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44 | // power of 2 (max 16*16 clusters / max 4 cores per cluster) |
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45 | // _ The array of values to be sorted (ARRAY_LENGTH) must be power of 2 |
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46 | // larger than the number of cores. |
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47 | /////////////////////////////////////////////////////////////////////////////// |
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48 | |
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49 | #include <stdio.h> |
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50 | #include <stdlib.h> |
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51 | #include <unistd.h> |
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52 | #include <pthread.h> |
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53 | #include <almosmkh.h> |
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54 | #include <hal_macros.h> |
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55 | |
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56 | #define ARRAY_LENGTH 2048 // number of items |
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57 | #define MAX_THREADS 1024 // 16 * 16 * 4 |
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58 | |
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59 | #define X_MAX 16 // max number of clusters in a row |
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60 | #define Y_MAX 16 // max number of clusters in a column |
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61 | #define CORES_MAX 4 // max number of cores in a cluster |
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62 | #define CLUSTERS_MAX X_MAX * Y_MAX |
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63 | |
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64 | #define USE_DQT_BARRIER 1 // use DQT barrier if non zero |
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65 | #define DISPLAY_ARRAY 0 // display items values before and after |
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66 | #define DEBUG_MAIN 0 // trace main function |
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67 | #define DEBUG_SORT 0 // trace sort function |
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68 | #define CHECK_RESULT 0 // for debug |
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69 | #define INSTRUMENTATION 1 // register computation times on file |
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70 | |
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71 | /////////////////////////////////////////////////////////////////////////////////// |
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72 | // Arguments for the sort() function |
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73 | /////////////////////////////////////////////////////////////////////////////////// |
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74 | |
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75 | typedef struct |
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76 | { |
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77 | unsigned int tid; // continuous thread index |
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78 | unsigned int threads; // total number of threads |
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79 | pthread_barrier_t * parent_barrier; // pointer on termination barrier |
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80 | } |
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81 | sort_args_t; |
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82 | |
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83 | //////////////////////////////////////////////////////////////////////////////////// |
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84 | // Sort specific global variables |
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85 | //////////////////////////////////////////////////////////////////////////////////// |
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86 | |
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87 | int array0[ARRAY_LENGTH]; // values to sort |
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88 | int array1[ARRAY_LENGTH]; |
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89 | |
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90 | pthread_barrier_t barrier; // synchronisation variables |
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91 | |
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92 | ///////////////////////////////////////////////////////////////////////////////////// |
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93 | // Global variables required by parallel_pthread_create() |
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94 | ///////////////////////////////////////////////////////////////////////////////////// |
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95 | |
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96 | // 2D arrays of input arguments for the <sort> threads |
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97 | // These arrays are initialised by the application main thread |
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98 | |
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99 | sort_args_t sort_args[CLUSTERS_MAX][CORES_MAX]; // sort function arguments |
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100 | sort_args_t * sort_ptrs[CLUSTERS_MAX][CORES_MAX]; // pointers on arguments |
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101 | |
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102 | // 1D array of barriers to allow the <sort> threads to signal termination |
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103 | // this array is initialised by the pthread_parallel_create() function |
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104 | |
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105 | pthread_barrier_t parent_barriers[CLUSTERS_MAX]; // termination barrier |
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106 | |
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107 | |
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108 | //////////////////////////////////// |
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109 | static void bubbleSort( int * array, |
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110 | unsigned int length, |
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111 | unsigned int init_pos ) |
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112 | { |
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113 | unsigned int i; |
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114 | unsigned int j; |
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115 | int aux; |
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116 | |
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117 | for(i = 0; i < length; i++) |
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118 | { |
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119 | for(j = init_pos; j < (init_pos + length - i - 1); j++) |
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120 | { |
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121 | if(array[j] > array[j + 1]) |
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122 | { |
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123 | aux = array[j + 1]; |
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124 | array[j + 1] = array[j]; |
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125 | array[j] = aux; |
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126 | } |
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127 | } |
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128 | } |
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129 | } // end bubbleSort() |
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130 | |
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131 | |
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132 | /////////////////////////////////// |
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133 | static void merge( const int * src, // source array |
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134 | int * dst, // destination array |
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135 | int length, // number of items in a subset |
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136 | int init_pos_src_a, // index first item in src subset A |
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137 | int init_pos_src_b, // index first item in src subset B |
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138 | int init_pos_dst ) // index first item in destination |
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139 | { |
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140 | int i; |
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141 | int j; |
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142 | int k; |
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143 | |
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144 | i = 0; |
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145 | j = 0; |
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146 | k = init_pos_dst; |
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147 | |
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148 | while((i < length) || (j < length)) |
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149 | { |
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150 | if((i < length) && (j < length)) |
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151 | { |
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152 | if(src[init_pos_src_a + i] < src[init_pos_src_b + j]) |
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153 | { |
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154 | dst[k++] = src[init_pos_src_a + i]; |
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155 | i++; |
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156 | } |
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157 | else |
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158 | { |
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159 | dst[k++] = src[init_pos_src_b + j]; |
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160 | j++; |
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161 | } |
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162 | } |
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163 | else if(i < length) |
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164 | { |
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165 | dst[k++] = src[init_pos_src_a + i]; |
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166 | i++; |
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167 | } |
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168 | else |
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169 | { |
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170 | dst[k++] = src[init_pos_src_b + j]; |
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171 | j++; |
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172 | } |
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173 | } |
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174 | } // end merge() |
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175 | |
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176 | ////////////////////////////// |
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177 | void sort( sort_args_t * ptr ) |
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178 | { |
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179 | unsigned int i; |
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180 | int * src_array = NULL; |
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181 | int * dst_array = NULL; |
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182 | |
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183 | // get arguments |
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184 | unsigned int tid = ptr->tid; |
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185 | unsigned int threads = ptr->threads; |
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186 | pthread_barrier_t * parent_barrier = ptr->parent_barrier; |
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187 | |
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188 | unsigned int items = ARRAY_LENGTH / threads; |
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189 | unsigned int stages = __builtin_ctz( threads ) + 1; |
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190 | |
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191 | #if DEBUG_SORT |
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192 | printf("\n[sort] start : ptr %x / tid %d / threads %d / barrier %x\n", |
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193 | ptr, tid, threads, parent_barrier ); |
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194 | #endif |
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195 | |
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196 | bubbleSort( array0, items, items * tid ); |
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197 | |
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198 | #if DEBUG_SORT |
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199 | printf("\n[sort] thread[%d] : stage 0 completed\n", tid ); |
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200 | #endif |
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201 | |
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202 | ///////////////////////////////// |
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203 | pthread_barrier_wait( &barrier ); |
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204 | |
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205 | #if DEBUG_SORT |
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206 | printf("\n[sort] thread[%d] exit barrier 0\n", tid ); |
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207 | #endif |
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208 | |
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209 | // the number of threads contributing to sort is divided by 2 |
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210 | // and the number of items is multiplied by 2 at each next stage |
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211 | for ( i = 1 ; i < stages ; i++ ) |
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212 | { |
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213 | if((i % 2) == 1) // odd stage |
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214 | { |
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215 | src_array = array0; |
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216 | dst_array = array1; |
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217 | } |
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218 | else // even stage |
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219 | { |
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220 | src_array = array1; |
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221 | dst_array = array0; |
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222 | } |
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223 | |
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224 | if( (tid & ((1<<i)-1)) == 0 ) |
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225 | { |
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226 | |
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227 | #if DEBUG_SORT |
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228 | printf("\n[sort] thread[%d] : stage %d start\n", tid , i ); |
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229 | #endif |
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230 | merge( src_array, |
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231 | dst_array, |
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232 | items << (i-1), |
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233 | items * tid, |
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234 | items * (tid + (1 << (i-1))), |
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235 | items * tid ); |
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236 | |
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237 | #if DEBUG_SORT |
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238 | printf("\n[sort] thread[%d] : stage %d completed\n", tid , i ); |
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239 | #endif |
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240 | } |
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241 | |
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242 | ///////////////////////////////// |
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243 | pthread_barrier_wait( &barrier ); |
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244 | |
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245 | #if DEBUG_SORT |
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246 | printf("\n[sort] thread[%d] exit barrier %d\n", tid , i ); |
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247 | #endif |
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248 | |
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249 | } // en for stages |
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250 | |
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251 | // sort thread signal completion to main thread |
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252 | pthread_barrier_wait( parent_barrier ); |
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253 | |
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254 | #if DEBUG_SORT |
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255 | printf("\n[sort] thread[%d] exit\n", tid ); |
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256 | #endif |
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257 | |
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258 | // sort thread exit |
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259 | pthread_exit( NULL ); |
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260 | |
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261 | } // end sort() |
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262 | |
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263 | |
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264 | ///////////////// |
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265 | void main( void ) |
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266 | { |
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267 | int error; |
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268 | unsigned int x_size; // number of rows |
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269 | unsigned int y_size; // number of columns |
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270 | unsigned int ncores; // number of cores per cluster |
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271 | unsigned int total_threads; // total number of threads |
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272 | unsigned int x; // X coordinate for a sort thread |
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273 | unsigned int y; // Y coordinate for a sort thread |
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274 | unsigned int cxy; // cluster identifier for a sort thead |
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275 | unsigned int lid; // core local index for a thread |
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276 | unsigned int tid; // sort thread continuous index |
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277 | pthread_barrierattr_t barrier_attr; // barrier attributes (used for DQT) |
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278 | unsigned int n; // index in array to sort |
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279 | |
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280 | unsigned long long start_cycle; |
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281 | unsigned long long seq_end_cycle; |
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282 | unsigned long long para_end_cycle; |
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283 | |
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284 | ///////////////////////// |
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285 | get_cycle( &start_cycle ); |
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286 | |
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287 | // compute number of threads (one thread per core) |
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288 | get_config( &x_size , &y_size , &ncores ); |
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289 | total_threads = x_size * y_size * ncores; |
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290 | |
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291 | // compute covering DQT size an level |
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292 | unsigned int z = (x_size > y_size) ? x_size : y_size; |
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293 | unsigned int root_level = (z == 1) ? 0 : (z == 2) ? 1 : (z == 4) ? 2 : (z == 8) ? 3 : 4; |
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294 | |
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295 | // checks number of threads |
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296 | if ( (total_threads != 1) && (total_threads != 2) && (total_threads != 4) && |
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297 | (total_threads != 8) && (total_threads != 16 ) && (total_threads != 32) && |
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298 | (total_threads != 64) && (total_threads != 128) && (total_threads != 256) && |
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299 | (total_threads != 512) && (total_threads != 1024) ) |
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300 | { |
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301 | printf("\n[sort] ERROR : number of cores must be power of 2\n"); |
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302 | exit( 0 ); |
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303 | } |
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304 | |
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305 | // check array size |
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306 | if ( ARRAY_LENGTH % total_threads) |
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307 | { |
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308 | printf("\n[sort] ERROR : array size must be multiple of number of threads\n"); |
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309 | exit( 0 ); |
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310 | } |
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311 | |
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312 | printf("\n[sort] main starts / %d threads / %d items / pid %x / cycle %d\n", |
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313 | total_threads, ARRAY_LENGTH, getpid(), (unsigned int)start_cycle ); |
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314 | |
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315 | // initialize barrier |
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316 | if( USE_DQT_BARRIER ) |
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317 | { |
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318 | barrier_attr.x_size = x_size; |
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319 | barrier_attr.y_size = y_size; |
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320 | barrier_attr.nthreads = ncores; |
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321 | error = pthread_barrier_init( &barrier, &barrier_attr , total_threads ); |
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322 | } |
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323 | else // use SIMPLE_BARRIER |
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324 | { |
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325 | error = pthread_barrier_init( &barrier, NULL , total_threads ); |
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326 | } |
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327 | |
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328 | if( error ) |
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329 | { |
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330 | printf("\n[sort] ERROR : cannot initialise barrier\n" ); |
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331 | exit( 0 ); |
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332 | } |
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333 | |
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334 | #if DEBUG_MAIN |
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335 | if( USE_DQT_BARRIER ) printf("\n[sort] main completes DQT barrier init\n"); |
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336 | else printf("\n[sort] main completes simple barrier init\n"); |
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337 | #endif |
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338 | |
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339 | // Array to sort initialization |
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340 | for ( n = 0 ; n < ARRAY_LENGTH ; n++ ) |
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341 | { |
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342 | array0[n] = ARRAY_LENGTH - n - 1; |
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343 | } |
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344 | |
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345 | #if DISPLAY_ARRAY |
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346 | printf("\n*** array before sort\n"); |
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347 | for( n=0; n<ARRAY_LENGTH; n++) printf("array[%d] = %d\n", n , array0[n] ); |
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348 | #endif |
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349 | |
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350 | #if DEBUG_MAIN |
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351 | printf("\n[sort] main completes array init\n"); |
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352 | #endif |
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353 | |
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354 | // build array of arguments for the <sort> threads |
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355 | for (x = 0 ; x < x_size ; x++) |
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356 | { |
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357 | for (y = 0 ; y < y_size ; y++) |
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358 | { |
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359 | // compute cluster identifier |
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360 | cxy = HAL_CXY_FROM_XY( x , y ); |
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361 | |
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362 | for ( lid = 0 ; lid < ncores ; lid++ ) |
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363 | { |
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364 | // compute thread continuous index |
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365 | tid = (((x * y_size) + y) * ncores) + lid; |
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366 | |
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367 | // initialize 2D array of arguments |
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368 | sort_args[cxy][lid].tid = tid; |
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369 | sort_args[cxy][lid].threads = total_threads; |
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370 | sort_args[cxy][lid].parent_barrier = &parent_barriers[cxy]; |
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371 | |
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372 | // initialize 2D array of pointers |
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373 | sort_ptrs[cxy][lid] = &sort_args[cxy][lid]; |
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374 | } |
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375 | } |
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376 | } |
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377 | |
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378 | /////////////////////////// |
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379 | get_cycle( &seq_end_cycle ); |
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380 | |
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381 | #if DEBUG_MAIN |
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382 | printf("\n[sort] main completes sequencial init at cycle %d\n", |
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383 | (unsigned int)seq_end_cycle ); |
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384 | #endif |
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385 | |
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386 | // create and execute the working threads |
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387 | if( pthread_parallel_create( root_level, |
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388 | &sort, |
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389 | &sort_ptrs[0][0], |
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390 | &parent_barriers[0] ) ) |
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391 | { |
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392 | printf("\n[sort] ERROR : cannot create threads\n"); |
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393 | exit( 0 ); |
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394 | } |
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395 | |
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396 | //////////////////////////// |
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397 | get_cycle( ¶_end_cycle ); |
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398 | |
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399 | #if DEBUG_main |
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400 | printf("\n[sort] main completes parallel sort at cycle %d\n", |
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401 | (unsigned int)para_end_cycle ); |
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402 | #endif |
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403 | |
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404 | // destroy barrier |
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405 | pthread_barrier_destroy( &barrier ); |
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406 | |
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407 | #if DISPLAY_ARRAY |
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408 | printf("\n*** array after merge %d\n", i ); |
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409 | for( n=0; n<ARRAY_LENGTH; n++) printf("array[%d] = %d\n", n , dst_array[n] ); |
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410 | #endif |
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411 | |
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412 | #if CHECK_RESULT |
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413 | int success = 1; |
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414 | int * res_array = ( (total_threads == 2) || |
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415 | (total_threads == 8) || |
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416 | (total_threads == 32) || |
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417 | (total_threads == 128) || |
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418 | (total_threads == 512) ) ? array1 : array0; |
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419 | |
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420 | for( n=0 ; n<(ARRAY_LENGTH-2) ; n++ ) |
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421 | { |
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422 | if ( res_array[n] > res_array[n+1] ) |
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423 | { |
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424 | printf("\n[sort] array[%d] = %d > array[%d] = %d\n", |
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425 | n , res_array[n] , n+1 , res_array[n+1] ); |
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426 | success = 0; |
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427 | break; |
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428 | } |
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429 | } |
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430 | |
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431 | if ( success ) printf("\n[sort] success\n"); |
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432 | else printf("\n[sort] failure\n"); |
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433 | #endif |
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434 | |
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435 | #if INSTRUMENTATION |
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436 | char name[64]; |
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437 | char path[128]; |
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438 | unsigned long long instru_cycle; |
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439 | |
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440 | // build file name |
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441 | if( USE_DQT_BARRIER ) |
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442 | snprintf( name , 64 , "p_sort_dqt_%d_%d_%d", ARRAY_LENGTH, x_size * y_size, ncores ); |
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443 | else |
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444 | snprintf( name , 64 , "p_sort_smp_%d_%d_%d", ARRAY_LENGTH, x_size * y_size, ncores ); |
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445 | |
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446 | // build file pathname |
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447 | snprintf( path , 128 , "home/%s" , name ); |
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448 | |
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449 | // compute results |
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450 | unsigned int sequencial = (unsigned int)(seq_end_cycle - start_cycle); |
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451 | unsigned int parallel = (unsigned int)(para_end_cycle - seq_end_cycle); |
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452 | |
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453 | // display results on process terminal |
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454 | printf("\n----- %s -----\n" |
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455 | " - sequencial : %d cycles\n" |
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456 | " - parallel : %d cycles\n", |
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457 | name, sequencial, parallel ); |
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458 | |
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459 | // open file |
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460 | get_cycle( &instru_cycle ); |
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461 | FILE * stream = fopen( path , NULL ); |
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462 | |
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463 | if( stream == NULL ) |
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464 | { |
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465 | printf("\n[sort] ERROR : cannot open instrumentation file <%s>\n", path ); |
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466 | exit(0); |
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467 | } |
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468 | |
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469 | printf("\n[sort] file <%s> open at cycle %d\n", path, (unsigned int)instru_cycle ); |
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470 | |
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471 | #if IDBG |
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472 | idbg(); |
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473 | #endif |
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474 | |
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475 | // register results to file |
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476 | get_cycle( &instru_cycle ); |
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477 | int ret = fprintf( stream , "\n----- %s -----\n" |
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478 | " - sequencial : %d cycles\n" |
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479 | " - parallel : %d cycles\n", name, sequencial, parallel ); |
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480 | if( ret < 0 ) |
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481 | { |
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482 | printf("\n[sort] ERROR : cannot write to instrumentation file <%s>\n", path ); |
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483 | exit(0); |
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484 | } |
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485 | |
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486 | printf("\n[sort] file <%s> written at cycle %d\n", path, (unsigned int)instru_cycle ); |
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487 | |
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488 | #if IDBG |
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489 | idbg(); |
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490 | #endif |
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491 | |
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492 | // close instrumentation file |
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493 | get_cycle( &instru_cycle ); |
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494 | ret = fclose( stream ); |
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495 | |
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496 | if( ret ) |
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497 | { |
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498 | printf("\n[sort] ERROR : cannot close instrumentation file <%s>\n", path ); |
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499 | exit(0); |
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500 | } |
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501 | |
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502 | printf("\n[sort] file <%s> closed at cycle %d\n", path, (unsigned int)instru_cycle ); |
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503 | |
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504 | #endif |
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505 | |
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506 | exit( 0 ); |
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507 | |
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508 | } // end main() |
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509 | |
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510 | /* |
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511 | vim: tabstop=4 : shiftwidth=4 : expandtab |
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512 | */ |
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