<div dir="ltr"><div>I use ThreadsPerCore=1 in the node definitions.</div><div><br></div><div>$ srun --cpus-per-task 1 --pty python3<br>Python 3.8.10 (default, Jun  2 2021, 10:49:15) <br>[GCC 9.4.0] on linux<br>Type "help", "copyright", "credits" or "license" for more information.<br>>>> import os<br>>>> os.cpu_count()<br>16<br>>>> os.sched_getaffinity(0)<br>{0}</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jul 12, 2021 at 12:18 PM Luis R. Torres <<a href="mailto:lrtorres@gmail.com" target="_blank">lrtorres@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi Folks,<div><br></div><div>





<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">I'm trying to run one task on one "core", however, when I test the affinity, the system gives me "two"; I'm assuming the two are threads since the system is a dual socket system.  Is there anything in the configuration that I can change to have a single core or thread assigned to a single-processing job by default?</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><br></span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">srun --ntasks=1 --cpus-per-task=1 show-affinity.py<span> </span></span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">pid 7899's current affinity mask: 401</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0);min-height:21px"><span style="font-variant-ligatures:no-common-ligatures"></span><br></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">=====================================</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">CPUs in system:<span>  </span>20</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">PID:<span>  </span>7899</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">Allocated CPUs/Cores:<span>  </span>2</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">Affinity List:<span>  </span>{0, 10}</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">=====================================</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:18px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><br></p><div><br></div>-- <br><div dir="ltr"><div dir="ltr"><div>----------------------------------------<br>Luis R. Torres<br></div></div></div></div></div>
</blockquote></div>