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<p class="MsoNormal"><span style="color:#1F497D">Thanks Hui. I will use MPI_Iprobe + MPI_Test.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Kurt<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b>From:</b> Zhou, Hui <zhouh@anl.gov> <br>
<b>Sent:</b> Thursday, June 4, 2020 10:27 AM<br>
<b>To:</b> discuss@mpich.org<br>
<b>Cc:</b> Mccall, Kurt E. (MSFC-EV41) <kurt.e.mccall@nasa.gov><br>
<b>Subject:</b> [EXTERNAL] Re: [mpich-discuss] Controlling MPICH busy-wait behavior<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">There is no such option for MPICH. If you configure with ch3:sock, which waits for the progress with blocking `poll`, I think it will not hog the CPU by default, for other configurations, it always busy waits.
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Is using MPI_Iprobe + MPI_Test an option for you? If your process can afford latency, then you can control your own sleep cycles between MPI_Test. If MPICH will implement such non-busy-wait option, internally it will just do the same test-sleep cycles.
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<p class="MsoNormal">-- <br>
Hui Zhou<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">"Mccall, Kurt E. (MSFC-EV41) via discuss" <<a href="mailto:discuss@mpich.org">discuss@mpich.org</a>><br>
<b>Reply-To: </b>"<a href="mailto:discuss@mpich.org">discuss@mpich.org</a>" <<a href="mailto:discuss@mpich.org">discuss@mpich.org</a>><br>
<b>Date: </b>Wednesday, June 3, 2020 at 3:57 PM<br>
<b>To: </b>"<a href="mailto:discuss@mpich.org">discuss@mpich.org</a>" <<a href="mailto:discuss@mpich.org">discuss@mpich.org</a>><br>
<b>Cc: </b>"Mccall, Kurt E. (MSFC-EV41)" <<a href="mailto:kurt.e.mccall@nasa.gov">kurt.e.mccall@nasa.gov</a>><br>
<b>Subject: </b>[mpich-discuss] Controlling MPICH busy-wait behavior<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Is there a means to tell MPICH to yield to other processes when performing a busy-wait for incoming messages? The page below distinguishes between “aggressive busy-wait” and “degraded busy-wait”, where the latter is what I’d like to try.<o:p></o:p></p>
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<p class="MsoNormal"><a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__stackoverflow.com_questions_14560714_probe-2Dseems-2Dto-2Dconsume-2Dthe-2Dcpu_14562840-2314562840&d=DwMGaQ&c=ApwzowJNAKKw3xye91w7BE1XMRKi2LN9kiMk5Csz9Zk&r=6cP1IfXu3IZOHSDh_vBqciYiIh4uuVgs1MSi5K7l5fQ&m=stZqd9Fs3P0zmm4350zML37qvC5jT4e9jhayHaxrcbw&s=auPT9hTHN3AOIqD0_f-gKxki1W12bFbMF-6s6AGIL_w&e=">https://stackoverflow.com/questions/14560714/probe-seems-to-consume-the-cpu/14562840#14562840</a><o:p></o:p></p>
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<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Kurt<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
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