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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Mahmoud,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks for the hint. I tried that out and
it definitely helped. The key parameter is the max_cmd_per_lun. I think at 16
(which is what I was using) it was overflowing something in the stack. I tried
both 3 and 5. With 5 I was able to get over 700 MB/s for one up to four LUNs
on a single port. I was able to get 750 MB/s when using over two LUNs. So
that looks much better.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Thanks,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>--Shane<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Mahmoud Hanafi
[mailto:mhanafi@csc.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, June 26, 2007 10:12
AM<br>
<b><span style='font-weight:bold'>To:</span></b> Canon, Richard Shane<br>
<b><span style='font-weight:bold'>Cc:</span></b> general@lists.openfabrics.org;
Vu Pham<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [ofa-general] low
performance with multiple LUNs on a single portwith ib_srp</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'><br>
</span></font><font size=2 face=sans-serif><span style='font-size:10.0pt;
font-family:sans-serif'>Here are some performance results that I was able to
achieve running across several Luns.</span></font> <br>
<br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>Config
setting</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>1
host port to 1 ddn port.</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>OFED1.2rc6</span></font>
<br>
<br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>[root@io1
IB]# cat /etc/modprobe.conf</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
scsi_hostadapter qla2xxx</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
scsi_hostadapter1 megaraid_sas</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
scsi_hostadapter2 qla2400</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
usb-controller ehci-hcd</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
usb-controller1 uhci-hcd</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
ib0 ib_ipoib</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
ib1 ib_ipoib</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
net-pf-27 ib_sdp</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
lustre llite</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>options
lnet networks=o2ib</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
eth1 bnx2</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>alias
eth0 bnx2</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>options
ib_srp srp_sg_tablesize=256<br>
<br>
[root@io1 IB]# cat /etc/srp_daemon.conf</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>a
max_sect=8192,max_cmd_per_lun=3</span></font> <br>
<br>
<br>
<br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>
Write (MB/sec)
</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>
Number of LUNS
</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>"Rec
Length</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> (KB)"
1 2
3 4 5
6 7</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 16
23
37 41
47 51 55
57 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 32
44
72 82
94 102 109
114 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 64
79
136 163
187 201 215
226 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 128
131
247 310
352 380
405 426 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 256
194
363 477
549 616
673 698 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 512
299
558 553
670 717
725 727 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 1,024
434
591 718
725 725
725 726 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 2,048
465
608 687
723 725
726 726 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 4,096
523
695 722
726 727
727 726 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 8,192
537
702 726
727 728
726 727 </span></font><br>
<br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>
Read (MB/sec)
</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>
Number of LUNS
</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'>"Rec
Length</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> (KB)"
1 2
3 4 5
6 7</span></font> <br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 16
26
41 45
56 60 63
62 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 32
48
78 97
107 117 122
124 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 64
81
140 172
196 215 227
237 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 128
126
207 269
314 347
373 391 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 256
174
271 389
482 500
537 546 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 512
255
375 418
478 528
556 562 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 1,024
330
430 505
554 564
564 564 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 2,048
326
445 527
553 561
563 564 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 4,096
357
513 556
562 564
564 565 </span></font><br>
<font size=2 face=sans-serif><span style='font-size:10.0pt;font-family:sans-serif'> 8,192
360
520 558
564 565
565 565 <br>
<br>
<br>
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<o:p></o:p></p>
<table class=MsoNormalTable border=0 cellpadding=0 width="100%"
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<tr>
<td width="40%" valign=top style='width:40.0%;padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><b><font size=1 face=sans-serif><span style='font-size:
7.5pt;font-family:sans-serif;font-weight:bold'>"Canon, Richard
Shane" <canonrs@ornl.gov></span></font></b><font size=1
face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'> </span></font><br>
<font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>Sent
by: general-bounces@lists.openfabrics.org</span></font> <o:p></o:p></p>
<p><font size=1 face=sans-serif><span style='font-size:7.5pt;font-family:
sans-serif'>06/25/2007 05:51 PM</span></font> <o:p></o:p></p>
</td>
<td width="59%" valign=top style='width:59.0%;padding:.75pt .75pt .75pt .75pt'>
<table class=MsoNormalTable border=0 cellpadding=0 width="100%"
style='width:100.0%'>
<tr>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal align=right style='text-align:right'><font size=1
face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>To</span></font><o:p></o:p></p>
</td>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><font size=1 face=sans-serif><span style='font-size:
7.5pt;font-family:sans-serif'>Vu Pham <vuhuong@mellanox.com></span></font>
<o:p></o:p></p>
</td>
</tr>
<tr>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal align=right style='text-align:right'><font size=1
face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>cc</span></font><o:p></o:p></p>
</td>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><font size=1 face=sans-serif><span style='font-size:
7.5pt;font-family:sans-serif'>general@lists.openfabrics.org</span></font> <o:p></o:p></p>
</td>
</tr>
<tr>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal align=right style='text-align:right'><font size=1
face=sans-serif><span style='font-size:7.5pt;font-family:sans-serif'>Subject</span></font><o:p></o:p></p>
</td>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><font size=1 face=sans-serif><span style='font-size:
7.5pt;font-family:sans-serif'>[ofa-general] low performance with multiple
LUNs on a single port with ib_srp</span></font><o:p></o:p></p>
</td>
</tr>
</table>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<table class=MsoNormalTable border=0 cellpadding=0>
<tr>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
</td>
<td valign=top style='padding:.75pt .75pt .75pt .75pt'>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
</td>
</tr>
</table>
<p class=MsoNormal><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'><o:p></o:p></span></font></p>
</td>
</tr>
</table>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<br>
<br>
</span></font><font size=2 face=Arial><span style='font-size:10.0pt;font-family:
Arial'> </span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Greetings,</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Hopefully
the subject says it all…</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>I’ve
stumbled on a performance issue with the OFED ib_srp driver. Here is the
configuration. I am testing with a DDN 9550 and a single host system.
The systems are connected by two SDR links. On the host side there
is a dual port (DDR) card. On the DDN side, both lines go into a single
singlet (even though it is a couplet). The lines go into two distinct
cards on the DDN side (if you are familiar with the layout). The testing
used OFED 1.2.</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Now
for the tests… If I run a single stream test I’m seeing good result with
over 700 MB/s. These tests are run using sg_dd with the directio flag.
If I run two concurrent streams against two LUNs that are each presented
over a single port on the DDN (and therefore accessed by a single port on the
host side), the aggregate performance drop to around 120 MB/s (60 MB/s per
stream).</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Just
to confirm it isn’t a problem on the DDN side, I repeated these tests with the
IBGD driver. There I consistently saw about 600-650 MB/s on the port
regardless of the number of LUNs I tested with.</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Any
ideas on what the problem is? Also, if this doesn’t make sense, let me
know and I will try to clarify further.</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Thanks,</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>--Shane
Canon</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> </span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>--</span></font>
<br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>R.
Shane Canon</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>National
Center for Computational Science</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Oak
Ridge National Laboratory</span></font> <br>
<font size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>canonrs@ornl.gov</span></font>
<br>
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