Product specifications

D–Troubleshooting
QLogic MPI Troubleshooting
D-12 IB6054601-00 H
S
Here is an example:
# cat /sys/class/infiniband/ipath*/device/irq
98
# ls /proc/irq
0 10 11 13 15 233 4 50 7 8 90
1 106 12 14 2 3 5 58 66 74 9
(Note that you cannot find 98.)
# cat /proc/interrupts|grep ib_ipath|awk \
’{print $1}’|sed -e ’s/://’
106
# echo 01 > /proc/irq/106/smp_affinity
Using the echo command immediately changes the processor affinity of an IRQ.
You can look at the stats in /proc/interrupts while the adapter is active to
observe which CPU is fielding ib_ipath interrupts.
Performance Warning if ib_ipath Shares Interrupts with
eth0
When ib_ipath shares interrupts with eth0, performance may be affected the
OFED ULPs, such as IPoIB. A warning message appears in syslog, and also on
the console or tty session where /etc/init.d/openibd start is run (if
messages are set up to be displayed). Messages are in this form:
Nov 5 14:25:43 <nodename> infinipath: Shared interrupt will
affect performance: vector 169: devices eth0, ib_ipath
Check /proc/interrupts: "169" is in the first column, and "devices" are shown
in the last column.
You can also contact your system vendor to see if the BIOS settings can be
changed to avoid the problem.
QLogic MPI Troubleshooting
Problems specific to compiling and running MPI programs are described in the
following sections.
NOTE:
 The contents of the smp_affinity file may not reflect the expected
values, even though the affinity change has taken place.
 If the driver is reloaded, the affinity assignment will revert to the default,
so you will need to reset it to the desired value.