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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi Zeus,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">At first look your program appears to be correct if sizeof(unsigned) == 4 on both source and destination. Although sending 4kB buffers through the IDC system
in this way is madness, it should work.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Unfortunately I’m not in a good position to run this right now (… it’s a long story involving snow and an out-of-date QEMU). When it fails, is the incorrect
value one from the previous iteration, or is it garbage?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">BTW, there is a minor use-after-free bug in your debug_printf() in the receive handler.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Andrew<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Zeus Gómez Marmolejo [mailto:zeus.gomez@bsc.es]
<br>
<b>Sent:</b> Monday, 16 January 2012 11:39<br>
<b>To:</b> barrelfish-users@lists.inf.ethz.ch<br>
<b>Subject:</b> [Barrelfish-users] Corruption sending buffer<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Dear Barrelfish developers,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I believe that I've found a bug in the message passing interface when a buffer is sent between two endpoints. I would like you to have a look at this example I'm sending to you. You can copy it to the folder "usr/tests/idctest" of the latest
version of the public repository. It should build correctly.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">This is a very simple example: it has 2 cores, with one thread per core. Only one core is sending a message to the other core. The message is a simple buffer of 1024 unsigned integers where the first integer and the last one is the same,
it's incremented in each message sent. The message handler on the receiver is just checking that the first and the last integer of the buffer are the same.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The application keeps running until it finds that the two integers differ. This means that the buffer has been sent incorrectly. I've tested this in qemu and in a real machine and after a while the program aborts because of a corrupt buffer.
In both systems, the error happens before 2 minutes approx.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Can you have a look at this example and check whether I'm doing something wrong? <br clear="all">
<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Many thanks!!<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">-- <br>
Zeus Gómez Marmolejo<br>
Barcelona Supercomputing Center<br>
PhD student<br>
<a href="http://www.bsc.es" target="_blank">http://www.bsc.es</a><br>
<br>
<o:p></o:p></p>
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