<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=us-ascii">
<META content="MSHTML 6.00.2900.3132" name=GENERATOR></HEAD>
<BODY>
<DIV><SPAN class=835524214-24072007><FONT face="Palatino Linotype"
color=#0000ff><STRONG>Hi Hal,</STRONG></FONT></SPAN></DIV>
<DIV><SPAN class=835524214-24072007><STRONG><FONT face="Palatino Linotype"
color=#0000ff></FONT></STRONG></SPAN> </DIV>
<DIV><SPAN class=835524214-24072007><STRONG><FONT face="Palatino Linotype"
color=#0000ff>What is this "loopback" connector used
for?</FONT></STRONG></SPAN></DIV>
<DIV><SPAN class=835524214-24072007><STRONG><FONT face="Palatino Linotype"
color=#0000ff>Does not seem to me like a very useful thing to
do.</FONT></STRONG></SPAN></DIV>
<DIV><SPAN class=835524214-24072007><STRONG><FONT face="Palatino Linotype"
color=#0000ff>Anyway, if it is not a production environment we could add a
"debug mode" (-d flag option) to ignore this check.</FONT></STRONG></SPAN></DIV>
<DIV> </DIV><!-- Converted from text/rtf format -->
<P><SPAN lang=en-gb><B><I><FONT face="Monotype Corsiva" color=#0000ff
size=6>Eitan Zahavi</FONT></I></B><I></I></SPAN> <BR><SPAN lang=en-gb><FONT
face=Tahoma size=2>Senior Engineering Director, Software Architect</FONT></SPAN>
<BR><SPAN lang=en-gb><FONT face=Tahoma size=2>Mellanox Technologies
LTD</FONT></SPAN> <BR><SPAN lang=en-gb><FONT face=Tahoma
size=2>Tel:+972-4-9097208<BR>Fax:+972-4-9593245</FONT></SPAN> <BR><SPAN
lang=en-gb><FONT face=Tahoma size=2>P.O. Box 586 Yokneam 20692
ISRAEL</FONT></SPAN> </P>
<DIV> </DIV><BR>
<BLOCKQUOTE dir=ltr
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid; MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> Hal Rosenstock
[mailto:hal.rosenstock@gmail.com] <BR><B>Sent:</B> Tuesday, July 24, 2007 5:31
PM<BR><B>To:</B> OpenFabrics General<BR><B>Cc:</B> Sasha Khapyorsky; Eitan
Zahavi; Yevgeny Kliteynik<BR><B>Subject:</B> OpenSM detection of duplicated
GUIDs on loopback<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV>Hi,</DIV>
<DIV> </DIV>
<DIV>This is what starts off as a "minor" issue and I know it has been
discussed it somewhat in the past: </DIV>
<DIV> </DIV>
<DIV>Putting a loopback connector on a (switch) link causes OpenSM to indicate
duplicated GUID error 0D18 as
follows:<BR><BR>__osm_ni_rcv_set_links<BR>{<BR>...<BR>
/*<BR>
When there are only two nodes with exact same guids (connected back
<BR>
to back) - the previous check for duplicated guid will not
catch<BR>
them. But the link will be from the port to
itself...<BR>
Enhanced Port 0 is an exception to
this<BR> */
<BR> if
((osm_node_get_node_guid( p_node ) == p_ni_context->node_guid)
&&<BR>
(port_num == p_ni_context->port_num)
&&<BR>
(port_num != 0))<BR>
{<BR>
osm_log( p_rcv->p_log, OSM_LOG_ERROR,
<BR>
"__osm_ni_rcv_set_links: ERR 0D18:
"<BR>
"Duplicate GUID found by link from a port to
itself:"<BR>
"node 0x%" PRIx64 ", port number 0x%X\n",
<BR>
cl_ntoh64( osm_node_get_node_guid( p_node )
),<BR>
port_num );<BR>...<BR><BR>So this occurs over and over and over and fills the
log with the same spew. This should be improved IMO. <BR><BR>Is this really a
fatal condition ? Doesn't seem like it should be to me. </DIV>
<DIV> </DIV>
<DIV>Also, OpenSM can "ride" this out with -y (stay on fatal) but is that safe
for this condition ?</DIV>
<DIV> </DIV>
<DIV>Seems like something like an extra loopback bit should be added to
some port structure which should cause these links to be ignored. This bit
would then be reset when the peer is now longer itself. <BR><BR>Also, is there
a relationship of this with the 12x/duplicated GUID code ? </DIV>
<DIV> </DIV>
<DIV>Thanks.</DIV>
<DIV> </DIV>
<DIV>-- Hal<SPAN class=sg></SPAN></DIV></BLOCKQUOTE></BODY></HTML>