HP-UX Reference (11i v2 07/12) - 1M System Administration Commands A-M (vol 3)

i
intctl(1M) intctl(1M)
To CPU ID (CPU H/W path)
The CPU id and CPU hardware path to which the interrupt will get migrated.
Redirection
The intctl command allows the performance specialist to modify the interrupt assignment of an inter-
face card. The user must specify the hardware path of interface card, the interrupt ID that needs to be
moved, and the new CPU ID that the interrupt will be routed to.
When an interrupt is moved from one CPU to another, if the interrupt shares a line with other interrupts,
all the interrupts on that line will be moved to the specified CPU. The kernel will add a message to the
/var/adm/syslog/syslog.log
file which will contain the hardware path and interrupt IDs of the
interrupts being moved and the CPU ID of the CPU to which these interrupts were moved.
When migrating an interrupt from one CPU to another, if the card that the interrupt belongs to is in an
erroneous or timed out state, the interrupt will not be moved. If an interrupt shares a line with other inter-
rupts, and if any of the cards is in an erroneous state, then none of the interrupts on the line will be moved
to the specified CPU.
Saving and Restoring System Interrupt Configurations
The
intctl command can save and restore the system interrupt configuration in a user specified file.
Before restoring the configuration, the intctl command checks to see if the system setup has changed by
checking that all the interface cards and CPUs from the saved configuration are still present in the system
and that the CPUs are in the same state as in the saved configuration. The command will continue to
restore the configuration if new cards or CPUs have been added to the system since the interrupt
configuration was saved.
Interrupt Configuration File
/etc/intctl.conf
is the interrupt configuration file.
intctl parameters can be saved in this configuration file, which makes them persistent across reboot.
These parameters can be changed or overridden by the command line options -i, -o and -a
.
The different sections in the
/etc/intctl.conf
configuration file described below.
1.
INTCTL_DRIVER_WEIGHTS
Each line after the above string is expected to be of the form driver_name weight. driver_name is a
string corresponding to the driver and weight is an integer corresponding to the driver’s weight. These
weights will be used while balancing interrupts using the
driver_weight
based algorithm. If a
driver is not specified in this section and is present on the system, then a default weight of
10 is
assumed. Weight can range from
0 to INT_MAX (see limits(5)). A
0 weight is considered as no inter-
rupt load. A positive integer is considered as the relative interrupt load on the CPU with respect to
different driver weights. More weight corresponds to more interrupt load on the CPU.
The option
-o drv:driver_name:weight can be used to override an existing driver weight or specify
new driver weights temporarily.
Example:
INTCTL_DRIVER_WEIGHTS
graf 300
2. INTCTL_HW_IGNORE
Each line after the above string is expected to be of the form hw_path intr_id. hw_path is a string
corresponding to the hardware path of the I/O card and intr_id is an integer corresponding to the inter-
rupt ID. The specified I/O card and the interrupt ID combination is ignored (that is, will not be
migrated) while balancing interrupts. If interrupt ID is -1, then all the interrupt IDs associated with
that I/O card are ignored.
The option -i io:hw_path:intr_id can be used to specify more I/O cards to be ignored temporarily.
NOTE: If an I/O card shares the interrupt line with another I/O card whose driver is non MP-safe, then
the interrupt of this I/O card cannot be migrated. intctl will display the following message if this
happens (the actual hardware path will be different):
"NOTE: I/O card <hardware_path> is sharing the interrupt line with another I/O
card which is claimed by a non MP-safe driver. Add the line ’hardware_path -1’
(hardware_path intr_id) to INTCTL_HW_IGNORE section of the configuration file
/etc/intctl.conf to avoid getting this message."
406 Hewlett-Packard Company − 6 − HP-UX 11i Version 2: December 2007 Update