<html>#2756: SystemTopology fails to handle Intel CPUs with performance and efficiency cores
<table style='border-spacing: 1ex 0pt; '>
<tr><td style='text-align:right'> Reporter:</td><td>Roland Haas</td></tr>
<tr><td style='text-align:right'> Status:</td><td>new</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td></td></tr>
<tr><td style='text-align:right'> Type:</td><td>bug</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>major</td></tr>
<tr><td style='text-align:right'>Component:</td><td>EinsteinToolkit thorn</td></tr>
</table>
<p>SystemTopology fails on new Intel CPUs with an assert similar to:</p>
<div class="codehilite"><pre><span></span><span class="n">cactus_sim</span><span class="o">:</span> <span class="n">configs</span><span class="sr">/sim/build/SystemTopology/s</span><span class="n">ystem_topology</span><span class="o">.</span><span class="na">cc</span><span class="o">:</span><span class="mi">471</span><span class="o">:</span> <span class="kc">void</span> <span class="o">{</span><span class="n">anonymous</span><span class="o">}::</span><span class="n">set_bindings</span><span class="o">(</span><span class="n">hwloc_topology_t</span><span class="o">,</span> <span class="kd">const</span> <span class="n">mpi_host_mapping_t</span><span class="o">&):</span> <span class="n">Assertion</span> <span>`</span><span class="n">num_pus</span> <span class="o">%</span> <span class="n">num_cores</span> <span class="o">==</span> <span class="mi">0</span><span>'</span> <span class="n">failed</span><span class="o">.</span>
</pre></div>
<p>where in the case of a 12th Gen Intel(R) Core(TM) i7-12700</p>
<p><a data-is-external-link="true" href="https://en.wikipedia.org/wiki/List_of_Intel_Core_i7_processors#Golden_Cove_+_Gracemont_microarchitecture_(12th_generation)" rel="nofollow">https://en.wikipedia.org/wiki/List_of_Intel_Core_i7_processors#Golden_Cove_+_Gracemont_microarchitecture_(12th_generation)</a></p>
<p>with performance (16) and efficiency (4) logical cpus hwloc reports:</p>
<p>core_depth 5<br>
num_cores 12<br>
pu_depth 6<br>
num_pus 20</p>
<p>and the assert `num_pus % num_cores == 0` fails (b/c only the 8 performance<br>
cores have hyperthreads).</p>
<p>This has been reported on the mailing list in <a data-is-external-link="true" href="https://lists.einsteintoolkit.org/pipermail/users/2023-August/009036.html" rel="nofollow">https://lists.einsteintoolkit.org/pipermail/users/2023-August/009036.html</a></p>
<p>Not sure if the asserted property is indeed required by SystemTopology or if this is only a sanity check that can be removed
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2756/systemtopology-fails-to-handle-intel-cpus'>https://bitbucket.org/einsteintoolkit/tickets/issues/2756/systemtopology-fails-to-handle-intel-cpus</a></p>
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