[openib-general] ip over ib throughtput

[Roland Dreier]

    Andras> I'm using 'modprobe ib_mthca msi_x=1', and 'MSI INIT
    Andras> SUCCESS' is there but /proc/interrupts doesn't show MSI
    Andras> being used so I'm puzzled a bit.  See dmesg output below.

It seems you have an ancient firmware version (1.18).  MSI-X will not
work correctly with firmware older than 3.3.2.  In fact it seems
likely that with your FW, the HCA does not even expose an MSI-X PCI
capability.  If you do lspci -v, do you see a capability like

        Capabilities: [40] MSI-X: Enable+ Mask- TabSize=32

or

        Capabilities: [40] #11 [801f]

for your HCA?  (Only alpha pciutils 2.1.99 can decode MSI-X
capabilities, so you'll probably see the second version if you see
anything).

If there is no such capability then the driver won't be able to enable
MSI-X interrupts and you'll see the behavior you describe.

 - R.