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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hello –<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’m from QLogic Corp, and I’m trying to port
some older applications to OFED, using the OFED stack and the OFED umad api
(specifically – opening the /dev/infiniband/umadX, and using read / write).
I am using OFED 1.2.5.<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'>My old application interrogates the SA, and also implements
the RMPP in the application layer. In porting this application to OFED, I
realize that the OFED stack has the capability to do the RMPP on my behalf, but
that has an adverse effect on my application since my infiniband interface in
my app transfers 256 byte packets ONLY. <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'>Hence – I want my app to do the RMPP, not OFED.<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'>So – I disabled RMPP support in OFED stack by
registering with RMPP version of 0. This seems effective in stopping OFED
stack from doing the RMPP for me. However – when I try to
send the RMPP ack, it fails at the write ().<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 investigated the OFED stack code, and its failing in ib_create_send_mad
(drivers/infiniband/core/mad.c). Investigation shows that if one
registered with RMPP version 0, then the ‘send’ never allows rmpp
to be active… (code snippet below)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> if
((!mad_agent->rmpp_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'>
(rmpp_active || message_size > sizeof(struct ib_mad))) ||<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>
(!rmpp_active && message_size > sizeof(struct ib_mad)))<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'> return
ERR_PTR(-EINVAL);<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'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>My questions are these:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>1. Has anyone tried an application layer supported RMPP ? If
so – how did you get past this logic (possible OFED bug??)<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'>2. Is the OFED implementation intent to disable RMPP support
COMPLETELY when registering with a RMPP version of 0? If so, then how
does one implement a user level RMPP using the OFED stack? Perhaps no one
is doing this at all since the stack already does it for you?<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'>Like I said – the only reason I’m doing this is
to port an old/ existing app to OFED, and there is a considerable level of
difficulty to rip our app level RMPP support. But perhaps this is the
alternative I must do…<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'>Anton Bodner<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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padding:1.0pt 0in 0in 0in'>
<p class=MsoNormal style='border:none;padding:0in'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'> </span></font><strong><b><font
face="Times New Roman"><span lang=FR>Anton Bodner Jr.</span></font></b></strong><span
lang=FR><o:p></o:p></span></p>
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<p class=MsoNormal><strong><b><font size=3 face="Times New Roman"><span
lang=FR style='font-size:12.0pt'>QLogic Corporation</span></font></b></strong><span
lang=FR><o:p></o:p></span></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=FR
style='font-size:10.0pt'>(610)233-4856</span></font><span lang=FR><o:p></o:p></span></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span lang=FR
style='font-size:10.0pt'>anton.bodner@qlogic.com</span></font><span lang=FR><o:p></o:p></span></p>
<p class=MsoNormal><font size=2 face="Times New Roman"><span style='font-size:
10.0pt'>http://www.qlogic.com</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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