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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I’ve been debugging an assert <CL_ASSERT( cur_seg
<= p_rmpp->seg_limit)> we see in function __process_segment in file cor\al\al_mad.c.
It looks like this happens infrequently, perhaps when processing IOC polling
responses (the GETTABLE query is IB_MAD_ATTR_NODE_RECORD).<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>It looks like what happens may be __process_segment is not
able to expand the MAD buffer via the call to al_resize_mad, perhaps due to
memory allocation failure. The failure happens (more?) under heavy server load.
The result seems to be the assert when the next query reply segment comes in.
It looks like the code assumes only the initial window of 1 segment is allowed
unless acked, but am not so sure the IB stack on the other end also uses an
initial window of only 1 segment (on Linux where the subnet manager is). Actually,
I’m not so sure the Windows subnet manager looks like it assumes an initial
window of 1. My guess is if the expansion of the MAD buffer goes ok, the pipelined
segments (past the window of 1) don’t break anything.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>We suspect if you set the ibbus parameter iocPollingInterval
to 0, this problem may go away. This might also mean it gets much worse with
much faster polling.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Does anybody else see this assert? Or have any comments on
this as a potential bug? This is in the 615 svn version.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Jan<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
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