1 | <?xml version="1.0" encoding="UTF-8"?> |
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2 | <!-- |
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3 | Copyright 2002-2004 The Apache Software Foundation |
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4 | |
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5 | Licensed under the Apache License, Version 2.0 (the "License"); |
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6 | you may not use this file except in compliance with the License. |
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7 | You may obtain a copy of the License at |
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8 | |
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9 | http://www.apache.org/licenses/LICENSE-2.0 |
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10 | |
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11 | Unless required by applicable law or agreed to in writing, software |
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12 | distributed under the License is distributed on an "AS IS" BASIS, |
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13 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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14 | See the License for the specific language governing permissions and |
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15 | limitations under the License. |
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16 | --> |
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17 | <!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd"> |
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18 | <document> |
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19 | <header> |
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20 | <title>The Hoard Multiprocessor Memory Allocator</title> |
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21 | </header> |
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22 | |
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23 | <!-- |
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24 | <articleinfo> |
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25 | <author> |
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26 | <firstname>Emery</firstname> |
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27 | <surname>Berger</surname> |
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28 | <affiliation>University of Massachusetts Amherst</affiliation> |
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29 | <street>Department of Computer Science</street> |
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30 | <city>Amherst</city> |
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31 | <state>Massachusetts</state> |
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32 | <country>USA</country> |
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33 | <email>emery@cs.umass.edu</email> |
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34 | </author> |
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35 | <pubdate>2004-12-08</pubdate> |
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36 | <copyright> |
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37 | <year>2004</year> |
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38 | <holder role="mailto:emery@cs.umass.edu">Emery Berger</holder> |
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39 | </copyright> |
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40 | <abstract> |
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41 | Documentation for the Hoard scalable memory allocator, including build and usage directions for several platforms. |
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42 | </abstract> |
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43 | </articleinfo> |
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44 | --> |
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45 | |
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46 | <body> |
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47 | |
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48 | <p class="quote"> |
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49 | ...if you'll be running on multiprocessor machines, ... <strong>use <a href="http://www.cs.umass.edu/~emery">Emery Berger</a>'s excellent Hoard multiprocessor memory management code</strong>. It's a drop-in replacement for the C and C++ memory routines and is very fast on multiprocessor machines. |
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50 | <em><a href="http://www.nerdbooks.com/item.php?id=0735615365">Debugging Applications for Microsoft .NET and Microsoft Windows</a>, Microsoft Press, 2003</em> |
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51 | </p> |
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52 | |
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53 | <!-- |
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54 | <p class="quote"> |
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55 | <strong>hoard:</strong> |
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56 | To amass and put away (anything valuable) for preservation, security, |
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57 | or future use; to treasure up: esp. money or wealth. |
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58 | <em>Oxford English Dictionary</em> |
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59 | </p> |
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60 | --> |
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61 | |
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62 | <p> |
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63 | The Hoard memory allocator is a fast, scalable, and memory-efficient |
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64 | memory allocator for shared-memory multiprocessors. It runs on a |
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65 | variety of platforms, including Linux, Solaris, and Windows. Hoard is |
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66 | a drop-in replacement for malloc(), etc. No change to your source is |
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67 | necessary. Just link it in or set just one environment variable (see |
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68 | <a href="using.html">Using Hoard</a> for more |
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69 | information). <strong>Hoard can dramatically improve the performance |
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70 | of multithreaded programs running on multiprocessors.</strong> |
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71 | |
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72 | |
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73 | </p> |
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74 | |
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75 | <section> |
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76 | <title>Why Hoard?</title> |
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77 | |
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78 | <p> |
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79 | There are a number of problems with existing memory allocators that make Hoard a better choice. |
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80 | </p> |
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81 | |
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82 | <section> |
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83 | <title>Contention</title> |
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84 | <p> |
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85 | Multithreaded programs often do not scale because the heap is a |
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86 | bottleneck. When multiple threads simultaneously allocate or |
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87 | deallocate memory from the allocator, the allocator will serialize |
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88 | them. Programs making intensive use of the allocator actually slow |
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89 | down as the number of processors increases. Your program may be |
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90 | allocation-intensive without you realizing it, for instance, if your |
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91 | program makes many calls to the C++ Standard Template Library (STL). |
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92 | </p> |
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93 | </section> |
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94 | <section> |
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95 | <title>False Sharing</title> |
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96 | <p> |
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97 | The allocator can cause other problems for multithreaded code. It can |
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98 | lead to <em>false sharing</em> in your application: |
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99 | threads on different CPUs can end up with memory in the same cache |
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100 | line, or chunk of memory. Accessing these falsely-shared cache lines |
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101 | is hundreds of times slower than accessing unshared cache lines. |
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102 | </p> |
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103 | </section> |
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104 | <section> |
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105 | <title>Blowup</title> |
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106 | <p> |
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107 | Multithreaded programs can also lead the allocator to blowup memory |
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108 | consumption. This effect can multiply the amount of memory needed to |
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109 | run your application by the number of CPUs on your machine: four CPUs |
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110 | could mean that you need four times as much memory. Hoard is a fast |
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111 | allocator that solves all of these problems. |
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112 | </p> |
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113 | </section> |
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114 | </section> |
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115 | |
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116 | <section> |
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117 | <title>Press</title> |
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118 | |
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119 | <p> |
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120 | <a href="http://www.intel.com/cd/ids/developer/asmo-na/eng/dc/xeon/43893.htm?page=4"><strong>Intel</strong> highlights the benefits of using Hoard</a> (a previous, slower version) on a 4-way Xeon system. |
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121 | </p> |
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122 | |
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123 | <p> |
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124 | <a href="http://developers.sun.com/solaris/articles/multiproc/multiproc.html"><strong>Sun</strong> concludes that Hoard is more space-efficient</a> than their own allocators. |
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125 | </p> |
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126 | |
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127 | </section> |
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128 | |
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129 | <!-- |
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130 | <section> |
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131 | <title>How Do I Use Hoard?</title> |
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132 | <p> |
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133 | Hoard is a drop-in replacement for malloc(), etc. No change to your source is necessary. Just link it in or set just one environment variable. See <a href="using.html">Using Hoard</a> for more information. |
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134 | </p> |
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135 | </section> |
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136 | --> |
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137 | |
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138 | |
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139 | <section> |
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140 | <title>Who's Using Hoard?</title> |
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141 | <p> |
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142 | Companies using Hoard in their products and servers include <a href="http://www.aol.com">AOL</a>, <a href="http://www.bt.com">British Telecom</a>, <a href="http://www.businessobjects.com">Business Objects</a> |
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143 | (formerly Crystal Decisions), <a href="http://www.entrust.com">Entrust</a>, <a href="http://www.novell.com">Novell</a>, <a href="http://www.openwave.com">OpenWave Systems</a> (for their |
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144 | Typhoon and Twister servers), and <a href="http://www.reuters.com">Reuters</a>. |
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145 | </p> |
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146 | |
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147 | <p> |
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148 | Open source projects using Hoard include the Bayonne GNU telephony |
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149 | server, the <a href="http://supertech.lcs.mit.edu/cilk/">Cilk</a> parallel |
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150 | programming language, the <a href="http://www.cs.dartmouth.edu/research/DaSSF/index.html">Dartmouth |
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151 | Scalable Simulation Framework</a>, and the <a href="http://www.gnu.org/software/commoncpp/">GNU Common C++</a> |
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152 | system. |
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153 | </p> |
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154 | |
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155 | <p> |
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156 | Hoard is also a part of several major Linux distributions, including Debian and Novell's SuSe. |
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157 | </p> |
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158 | </section> |
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159 | |
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160 | |
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161 | <section> |
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162 | <title>More Information</title> |
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163 | <p> |
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164 | The first place to look for Hoard-related information is at the Hoard |
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165 | web page, <a href="http://www.hoard.org">www.hoard.org</a>. |
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166 | </p> |
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167 | |
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168 | <p> |
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169 | There are two mailing lists you should join if you are a |
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170 | user of Hoard. If you are just interested in being informed of new |
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171 | releases, join the <a |
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172 | href="http://groups.yahoo.com/group/hoard-announce/">Hoard-Announce</a> |
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173 | list. For general Hoard discussion, join the <a |
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174 | href="http://groups.yahoo.com/group/hoard/">Hoard</a> mailing |
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175 | list. You can also search the archives of these lists. |
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176 | </p> |
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177 | </section> |
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178 | |
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179 | |
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180 | <section> |
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181 | <title>Technical Information</title> |
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182 | <p> |
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183 | For technical details of a previous version of Hoard, read <a href="http://www.cs.umass.edu/~emery/hoard/asplos2000.pdf">Hoard: A Scalable Memory Allocator for Multithreaded Applications</a>, by Emery D. Berger, Kathryn S. McKinley, Robert D. Blumofe, and Paul R. Wilson. The Ninth International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS-IX). Cambridge, MA, November 2000. |
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184 | </p> |
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185 | </section> |
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186 | |
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187 | </body> |
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188 | </document> |
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