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<TITLE>RE: [openib-general] Shared Receive Queue</TITLE>
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<P><FONT SIZE=2>The performance of SRQ was improved to be identical to regular QP in the latest FW release for all devices.</FONT>
<BR><FONT SIZE=2>Tziporet</FONT>
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<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: Galen M. Shipman [<A HREF="mailto:gshipman@lanl.gov">mailto:gshipman@lanl.gov</A>]</FONT>
<BR><FONT SIZE=2>Sent: Tuesday, July 26, 2005 5:57 PM</FONT>
<BR><FONT SIZE=2>To: Or Gerlitz</FONT>
<BR><FONT SIZE=2>Cc: openib-general@openib.org</FONT>
<BR><FONT SIZE=2>Subject: Re: [openib-general] Shared Receive Queue</FONT>
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<P><FONT SIZE=2>I am using our own software which uses send receive in both cases. As </FONT>
<BR><FONT SIZE=2>I said the code paths are exactly the same except for posting of </FONT>
<BR><FONT SIZE=2>receive descriptors as well as initialization.</FONT>
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<P><FONT SIZE=2>- Galen</FONT>
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<P><FONT SIZE=2>On Jul 26, 2005, at 8:49 AM, Or Gerlitz wrote:</FONT>
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<P><FONT SIZE=2>>> We have software which uses the mellanox shared receive queue and we</FONT>
<BR><FONT SIZE=2>>> are seeing a substantial performance penalty (on the order of 4-5</FONT>
<BR><FONT SIZE=2>>> usec on 0 byte messages).</FONT>
<BR><FONT SIZE=2>>></FONT>
<BR><FONT SIZE=2>></FONT>
<BR><FONT SIZE=2>> Are you comparing code that sends short messages either by rdma write</FONT>
<BR><FONT SIZE=2>> where the</FONT>
<BR><FONT SIZE=2>> reciever does polling on memory (as done in some IB MPIs "short </FONT>
<BR><FONT SIZE=2>> message</FONT>
<BR><FONT SIZE=2>> protocols")</FONT>
<BR><FONT SIZE=2>> to code that uses send/recv with SRQ --or-- code that does send/recv</FONT>
<BR><FONT SIZE=2>> where in one run</FONT>
<BR><FONT SIZE=2>> the recv is to "non shared" queue (that is regular QP) and in the </FONT>
<BR><FONT SIZE=2>> other</FONT>
<BR><FONT SIZE=2>> run to SRQ (QP attached to SRQ)?</FONT>
<BR><FONT SIZE=2>></FONT>
<BR><FONT SIZE=2>> Or.</FONT>
<BR><FONT SIZE=2>></FONT>
<BR><FONT SIZE=2>></FONT>
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