Quoting r. Woodruff, Robert J [EMAIL PROTECTED]:
Subject: Drop in performance on Mellanox MT25204 single port DDR HCA
Hi Roland/Michael,
One of my coworkers in Champaign is seeing a performance
issue with the latest SVN driver and the OFED 1.1 Mellanox
driver on certain platforms.
At 02:43 PM 10/2/2006, Roland Dreier wrote:
Robert Yes. 1250Mbytes/sec is what we expect. You say the 128
Robert value comes from the BIOS ? If so, we need to discuss this
Robert with our BIOS team to find out why they limit it to 128,
Robert perhaps it is a BIOS bug.
Yes, I
Hi Roland/Michael,
One of my coworkers in Champaign is seeing a performance
issue with the latest SVN driver and the OFED 1.1 Mellanox
driver on certain platforms.
On the older SVN somewhere around 7500 the Mellanox driver
did not save and restore certain PCI registers before a reset.
Does using the tune_pci=1 module option for ib_mthca bring the
performance back up?
The reason the driver was changed to work this way is that presumably
the BIOS is setting the PCI configuration as it does for a reason. So
you might want investigate why the BIOS sets MaxReadReq down to 128 in
Roland wrote,
However tune_pci=1 will make the driver override this setting if you
really know what you're doing.
- R.
Peter, can you give this a try ?
I think you set this in /etc/modprobe.conf
add the line,
options mthca tune_pci=1
Also, we need to understand why the BIOS in your platform
Adding:
Options ib_mthca tune_pci=1
Puts MaxReadReq = 4096.
I get 1250MB/s bandwidth.
-- Peter
-Original Message-
From: Woodruff, Robert J
Sent: Monday, October 02, 2006 3:51 PM
To: Roland Dreier; Hartman, Peter
Cc: Michael S. Tsirkin; openib-general; EWG; Hartman, Peter
Subject:
Adding:
Options ib_mthca tune_pci=1
Puts MaxReadReq = 4096.
I get 1250MB/s bandwidth.
Is that good? I lost track from the beginning of the thread.
I would suggest working with your platform people to figure out why
the BIOS is setting the PCI Express parameters to non-optimal
Roland wrote,
Is that good? I lost track from the beginning of the thread.
I would suggest working with your platform people to figure out why
the BIOS is setting the PCI Express parameters to non-optimal values.
- R.
Yes. 1250Mbytes/sec is what we expect.
You say the 128 value comes from
Robert Yes. 1250Mbytes/sec is what we expect. You say the 128
Robert value comes from the BIOS ? If so, we need to discuss this
Robert with our BIOS team to find out why they limit it to 128,
Robert perhaps it is a BIOS bug.
Yes, I believe that the BIOS is the only place that
