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<p class="MsoNormal">Hello libfabric users,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am working on bringing up code that will be transferring data via RoCE among Linux and Windows hosts equipped with Mellanox ConnectX-5 NICs.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We have Linux to Linux communication working fine with the verbs provider. I am encountering some issues with the netdir provider on Windows. I am using version 1.13.0 of libfabric at the moment.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I will do my best to limit each thread to a single issue so as not to confuse any follow on discussion.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So, the first place our code stumbled was with a call to fi_endpoint on the subscribing side. It returned FI_OTHER, which was not super helpful. Digging deeper into the netdir provider layer of the code, I could see that Network Direct
call was returning ND_INSUFFICIENT_RESOURCES.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In searching for a reason, I stumbled across a <a href="https://docs.mellanox.com/display/winof2v27051000/Known+Issues">
known issue with the Mellanox NIC</a>:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">2690140<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><o:p> </o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b>Description:</b> Requests of QPs with a string of values set to "max" (e.g., Max Queue Depth + Max SGE counter + Max inline Data size) cannot be processed by the driver as their
accumulative size overcomes the WQ maximum size.<o:p></o:p></p>
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<p class="MsoNormal"><b>Workaround:</b> N/A<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b>Keywords:</b> ND QP creation <o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b>Detected in version: </b>2.70.50000<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I was hoping to find that I could control the values that were requested, but that appears not to be the case. I found the code in question, prov/netdir/src/netdir_ep.c:ofi_nd_ep_control, was simply passing in the maximum values it obtained
from an earlier query.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When I just blindly cut the values for MaxReceiveQueueDepth and MaxInitiatorQueueDepth by 50%, the routine started returning FI_SUCCESS.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So, for now, I am just leaving that hack in place and building a locally modified version of libfabric in order to proceed.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It seems to me that since the values being utilized are maximums, that it would be reasonable to expect to be able to query them via fi_getopt and then choose something other than the default via fi_setopt. I am new to libfabric, so perhaps
there is already some other mechanism in place to achieve this that I am unaware of.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks for the help,<o:p></o:p></p>
<p class="MsoNormal">Derek<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Derek Shinaberry<o:p></o:p></p>
<p class="MsoNormal">Senior Software Engineer, Platform Software<o:p></o:p></p>
<p class="MsoNormal">Canon Medical Research USA, Inc. <br>
706 N. Deerpath Drive, Vernon Hills, IL 60061, USA<br>
<a href="http://www.research.us.medical.canon/"><span lang="EN-AU">www.</span>research.us.medical.canon</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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