On 2016-09-22 12:44:00 [+0000], Koehrer Mathias (ETAS/ESW5) wrote: > I run the cyclictest with the following options: > # cyclictest -a -i 100 -d 10 -m -n -t -p 80 there is -S. And then 100 might be a little tight. > Of course the 2 minutes run-time of cyclictest is only a rough first estimate. and with no load… > Once I configure one of the i350 ports > # ifconfig eth2 up 192.168.100.100 > the cyclictest shows directly and reproducibly significant larger max latency values (40 microseconds, using the same conditions). > > > I did the very same test with kernel version 3.18.27-rt27. > With that version I did not see anything like that. > > Also, only the igb driver seems to cause the trouble. I have also an e1000e based NIC in this PC and > the usage of this driver does not add any significant latency. > > Any idea on this? Does this also happen if you have the NIC up and you plug in / out the cable? There are two things that come to mind: https://lkml.kernel.org/r/1445465268-10347-1-git-send-email-jonathan.david@xxxxxx https://lkml.kernel.org/r/1445886895-3692-1-git-send-email-joshc@xxxxxx > Thanks for any feedback > > Best regards > > Mathias Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
