[176] | 1 | <?xml version="1.0" encoding="UTF-8"?> |
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| 2 | <!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd"> |
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| 3 | <document> |
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| 4 | <header> |
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| 5 | <title>Hoard Frequently Asked Questions</title> |
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| 6 | </header> |
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| 7 | |
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| 8 | <body> |
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| 9 | <section> |
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| 10 | <title> |
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| 11 | What kind of applications will Hoard speed up? |
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| 12 | </title> |
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| 13 | <p> |
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| 14 | Hoard will always improve the performance of multithreaded programs |
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| 15 | running on multiprocessors that make frequent use of the heap (calls |
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| 16 | to malloc/free or new/delete, as well as many STL functions). Because |
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| 17 | Hoard avoids false sharing, Hoard also speeds up programs that only |
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| 18 | occasionally call heap functions but access these objects frequently. |
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| 19 | </p> |
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| 20 | </section> |
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| 21 | |
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| 22 | |
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| 23 | <section> |
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| 24 | <title> |
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| 25 | I'm using the STL but not seeing any performance improvement. Why not? |
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| 26 | </title> |
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| 27 | <p> |
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| 28 | In order to benefit from Hoard, you have to tell STL to use malloc instead of its internal custom memory allocator: |
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| 29 | </p> |
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| 30 | |
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| 31 | <source> |
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| 32 | typedef list<unsigned int, malloc_alloc> mylist; |
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| 33 | </source> |
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| 34 | |
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| 35 | </section> |
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| 36 | |
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| 37 | |
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| 38 | <section><title> |
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| 39 | What systems does Hoard work on? |
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| 40 | </title> |
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| 41 | <p> |
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| 42 | Hoard has been successfully tested on numerous Windows, Linux and |
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| 43 | Solaris systems, including a 4-processor x86 box running Windows |
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| 44 | NT/2000, a 4-processor x86 box running RedHat Linux 6.0 and 6.1, and a |
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| 45 | 16-processor Sun Enterprise server running Solaris. |
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| 46 | </p> |
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| 47 | </section> |
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| 48 | |
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| 49 | |
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| 50 | <section><title> |
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| 51 | Have you compared Hoard with SmartHeap SMP? |
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| 52 | </title> |
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| 53 | <p> |
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| 54 | We tried SmartHeap SMP but it did not work on our Suns (due to an |
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| 55 | apparent race condition in the code). |
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| 56 | </p> |
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| 57 | </section> |
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| 58 | |
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| 59 | |
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| 60 | <section> |
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| 61 | <title> |
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| 62 | Have you compared Hoard against mtmalloc or libumem? |
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| 63 | </title> |
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| 64 | <p> |
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| 65 | Yes. Hoard is much faster than either. For example, here's an |
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| 66 | execution of threadtest on Solaris: |
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| 67 | </p> |
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| 68 | <table> |
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| 69 | <tr> |
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| 70 | <td>Default:</td> |
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| 71 | <td>4.60 seconds</td> |
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| 72 | </tr> |
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| 73 | <tr> |
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| 74 | <td>Libmtmalloc:</td> |
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| 75 | <td>6.23 seconds</td> |
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| 76 | </tr> |
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| 77 | <tr> |
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| 78 | <td>Libumem:</td> |
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| 79 | <td>5.47 seconds</td> |
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| 80 | </tr> |
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| 81 | <tr> |
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| 82 | <td>Hoard 3.2:</td> |
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| 83 | <td>1.99 seconds</td> |
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| 84 | </tr> |
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| 85 | </table> |
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| 86 | </section> |
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| 87 | |
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| 88 | <section> |
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| 89 | <title> |
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| 90 | Can I use Hoard with a commercial application? |
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| 91 | </title> |
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| 92 | <p> |
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| 93 | Yes. Hoard is available under two licenses. The first license is the |
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| 94 | GNU General Public License. That license is free, but it requires you |
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| 95 | to open-source your application. The second option is to purchase a |
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| 96 | license from the University of Texas at Austin. Click the "Licensing Info" |
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| 97 | link on the left for more information. |
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| 98 | </p> |
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| 99 | |
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| 100 | </section> |
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| 101 | |
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| 102 | </body> |
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| 103 | </document> |
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