Re: RSS mode performance in ixgbe (82599) driver

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