[ofa-general] which CPU will ib_mthca interrupt next?

[Rick Jones]

I've gotten around to loading-up the GQ OFED 1.2 bits on a pair of RHEL5 
systems and was going to reproduce the tests I ran with the OFED 1.1 (?) 
bits which shipped with RHEL5.

However I've run into a little snag.

I've no idea which CPU ib_mthca will interrupt next.  ISTR (but could be 
wrong) that as I repeated a test with the 1.1 bits that the same CPU 
would be interrupted, but with 1.2 it seems that the 
card/firmware/whatever is deciding to migrate interrupts around.

I don't mind especially, I just want to know when/how it is going to do 
it, because I want to take measurments from when netperf/netserver is 
running on the CPU taking interrupts and when it is not.  That 
presupposes I know which CPU will take the interrupts.  I suppose I 
could just hit smp_affinity with a single CPU assignemnt, but I would 
like to avoid that if I can.

Bits of clue or pointers to fine manuals would be most appreciated,

rick jones

[root at hpcpc107 ~]# cat /proc/interrupts | grep ib
  77:    1331747     803705         80     732093       PCI-MSI-X 
ib_mthca (comp)
  78:       1506        172         42        123       PCI-MSI-X 
ib_mthca (async)