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<p>Hi Gestió,</p>
<p><br>
</p>
<p>To reliably load down 32 cores and view it:<br>
</p>
<p><br>
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<p>[user@headnode] <strong>srun -c 32 -t 10 --pty $SHELL</strong></p>
<p>[user@worknode] <strong>stress -c 32 -vm 32&<br>
</strong></p>
<p>[user@worknode]<strong> </strong><strong>htop; fg</strong></p>
<p>^C<br>
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<p><br>
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<p>You can view a task's CPU affinity by pressing <strong>a</strong> in htop if stress isn't consuming all the cores.<br>
<strong></strong></p>
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<p>You will need to make sure you have set <strong>TaskPlugin=</strong><strong>affinity</strong> (or cgroups) in your slurm.conf so processes are constrained to a given set of CPUs.<br>
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<p>Linux assigns numbers to your CPUs. 0-15 will be socket 1, thread 1. 16-31 are socket 2, thread 1, 32-47 are socket 1, thread 2. 48-63 are socket 2, thread 2. Slurm will use the first N CPUs.</p>
<p><br>
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If your current configuration isn't using all of, but only the first socket, you could try:
<p><br>
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<p><strong>Boards=1 SocketsPerBoard=1 CoresPerSocket=32 ThreadsPerCore=1</strong></p>
<p><br>
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<p>But I thing you might be stuck with half of each or starting slurmd with a set affinity mask via
<strong>taskset</strong>.<br>
</p>
<p><strong></strong><br>
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<p>Kind regards,</p>
<p> Sam</p>
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<div style="font-family:Calibri,Arial,Helvetica,sans-serif; text-align:right"><span style="font-size:large">Sam Hawarden</span></div>
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<div style="font-family:Calibri,Arial,Helvetica,sans-serif; text-align:right">Assistant Research Fellow</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; text-align:right">Pathology Department</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; text-align:right">Dunedin School of Medicine</div>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> slurm-users <slurm-users-bounces@lists.schedmd.com> on behalf of Gestió Servidors <sysadmin.caos@uab.cat><br>
<b>Sent:</b> Tuesday, 19 February 2019 03:52<br>
<b>To:</b> slurm-users@lists.schedmd.com<br>
<b>Subject:</b> [slurm-users] Only one socket for SLURM</font>
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<div>Hi,<br>
<br>
One node of my cluster has 2 CPU sockets (with 2 32-cores CPUs). Now, I would like to configure my SLURM to share only CPUs of first socket. I have configured slurm.conf in this way:<br>
<blockquote>NodeName=mynode CPUs=32 SocketsPerBoard=1 CoresPerSocket=16 ThreadsPerCore=2 RealMemory=515703 TmpDisk=270000<br>
</blockquote>
but, with this line, how can I know slurm is using only firsts 32 cores (or seconds 32 cores) and not 16 of first and others 16 of the other socket?<br>
<br>
Thanks.<br>
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