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
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
