Michael Chan wrote:
On Thu, 2005-06-09 at 18:24 -0700, Ben Greear wrote:
Michael Chan wrote:
Unfortunately, the 5704 requires the "ONE_DMA" workaround which will
limit throughput in a PCIX 100/133 bus. If you comment out the line that
sets the DMA_RWCTRL_ONE_DMA flag in tg3.c, you should see improved
performance. However, you may run into some DMA issues on certain
systems.
Is there any way I can tell which systems are affected? It won't be
an option for me to purposefully ship possibly busted drivers/hardware,
but if I can be certain that my systems are immune, I will try this
modification.
I mentioned this so that you could verify that the slow performance was
indeed caused by ONE_DMA. Even if your system is affected, it's a very
subtle problem that won't show up right away and should allow you to get
some performance numbers.
I commented out the code and ran the pktgen test again. It may be a small
bit better, but not much: 770Mbps in one direction, 750Mbps in the other.
Have you done any tests with 2 tg3 NICs in a single machine to see if they
can run at or near line speed (full duplex)?
Thanks,
Ben
--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc http://www.candelatech.com
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