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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Hi Yonghong!<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">The documentation says:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#666666;background:#F2F2F2">Sets the number of milliseconds that a thread should wait, after completing the execution of a parallel region, before sleeping.
This routine affects the block time setting for the calling thread and any OpenMP* team threads formed by the calling thread.</span><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">The key words here is “formed by the calling thread”. That means there is no race conditions here as each thread only
sets its own control variable. Calling the setter from inside the parallel region will affect nested parallel regions created by the calling thread, this does not affect current team members.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Andrey<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><a name="_____replyseparator"></a><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Openmp-dev [mailto:openmp-dev-bounces@lists.llvm.org]
<b>On Behalf Of </b>Yonghong Yan via Openmp-dev<br>
<b>Sent:</b> Friday, July 1, 2016 11:02 PM<br>
<b>To:</b> openmp-dev@lists.llvm.org<br>
<b>Subject:</b> [Openmp-dev] kmp_set_blocktime<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US">I am a bit confused with the usage and purpose of kmp_set_blocktime: <o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US">From <o:p></o:p></span></p>
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<p class="MsoNormal"><a href="https://software.intel.com/en-us/node/522688#4ED418BA-EE4F-4A37-BCB9-88B114D8FA21"><span lang="EN-US">https://software.intel.com/en-us/node/522688#4ED418BA-EE4F-4A37-BCB9-88B114D8FA21</span></a><span lang="EN-US"> and the source
code (</span><a href="http://vm:8080/llvm/s?refs=__kmp_aux_set_blocktime"><b><i><span lang="EN-US" style="color:#990099;text-decoration:none">__kmp_aux_set_blocktime</span></i></b></a><span lang="EN-US">), the set_block_time change the block time for the calling
thread and the team threads, no body else. <o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US">If the function is called in the sequential region, there is no team during the region. if it should be called in the parallel region, it should be in a critical section (or called by one thread only) so do not introduce
traces since the call clearly updates some fields in the team object. I assume the intention is the latter case, which is for impacting the waiting behavior of the team thread after a parallel region. It however would not impact the them after the parallel
region since the team is gone by that. did I miss anything?<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal">Yonghong<o:p></o:p></p>
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