RSS mode performance in ixgbe (82599) driver

August 09th, 2011 - 08:10 am ET by J.Hwan Kim | Report spam
Hi, everyone

I'm testing the RSS mode throughput of Intel ixgbe 82599 driver.
My server's specification is Xeon 3GHz (4cores) and PCIe speed is
2.5Gx8lanes,
and DD2 memory is about 600~700MHz.

When I enable the RSS(receive side scaling) mode with 4 Rx queues,
the Rx performance is below than when I use a single queue.

I don't know how the cores operate, whether the cores run in sequence
or simultaneously at the same time.

I want to know the mechanism in general how the multi-cores run
and the reason why the performance of ixgbe driver in rss mode is below
non-rss mode.

Thanks in advance.

Best Regards,
J.Hwan Kim





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#1 Eric Dumazet
August 09th, 2011 - 08:50 am ET | Report spam
Le mardi 09 août 2011 à 21:03 +0900, J.Hwan Kim a écrit :
Hi, everyone

I'm testing the RSS mode throughput of Intel ixgbe 82599 driver.
My server's specification is Xeon 3GHz (4cores) and PCIe speed is
2.5Gx8lanes,
and DD2 memory is about 600~700MHz.

When I enable the RSS(receive side scaling) mode with 4 Rx queues,
the Rx performance is below than when I use a single queue.

I don't know how the cores operate, whether the cores run in sequence
or simultaneously at the same time.

I want to know the mechanism in general how the multi-cores run
and the reason why the performance of ixgbe driver in rss mode is below
non-rss mode.



CC netdev, as these kind of stuff is better hosted on netdev

You should make sure your 4 rx queues are serviced by different cpus, or
else, one cpu could be the bottleneck.

cat /proc/interrupts



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