Hi, I'm running Linux 4.3.3 (Gentoo) and standard igb drivers. I have trouble with the performance of IPSec on my platform. The platform has Intel Ethernet Controller I211 (1GbE) and Intel Atom CPUs (4-core) from the C2000 product family.
My platform only seems to be able to do ~300Mbit/s when receiving IPSec packets. When sending IPSec packets it can do ~600Mbit/s. The weird thing is, the ksoftirqd handler seems to run at very high CPU load. I don't understand where that comes from. I have traced using kernel function tracing and I can see that it is taking a lot of time do handle do_softirq and functions like igb_poll(). I was wondering if it was normal that this takes up so much CPU? Also it seems that this is only the case in the following scenario: The platform receives IPSec packets on eth0, then decrypts them, and routes them out via eth1 (plaintext). The packet stream is TCP. So for each amount of packets going this way, there is an TCP ACK packet going back the other way. E.g. plaintext incoming via eth1, IPSec encryption and TX out via eth0. For me this sounds like a very normal use case of IPSec, but still the platform does not seem to be able to handle it. As my CPU load is high, but not maxed out, the CPU does not seem to be the bottleneck. So my guess is it might also be the NIC. I do not have any configuration options in my igb driver, and I already tried a few option with ethtool, but I don't get any improvements. Does anyone have a good idea on how to track what is slowing down the system? Many thanks, Anna ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
