intctl.1m (2010 09)

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intctl(1M) intctl(1M)
The following descriptions explain each column in the table:
Sl. Num. Serial number (starting from 1) of all the migrations that will be performed for
balancing of interrupts. These serial numbers can be used in selecting migrations
that have to be skipped.
Card H/W Path The hardware path of I/O cards whose interrupt is getting migrated.
Driver name The driver associated with the card.
Intr ID The identity of the interrupt to be moved.
From CPU ID (CPU H/W path)
The CPU ID and CPU hardware path to which the interrupt is currently bound,
and the interrupt will be migrated off this CPU.
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 to which the interrupt belongs is in
timed-out state, from either a SUSPEND or RESUME operation (see olrad (1M)), then the interrupt will
not be moved. If an interrupt shares a line with other interrupts, and if any of the cards is in timed-out
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
(see the -s file and -r file options). 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. The intctl parameters can be saved in this
configuration file, which makes them persistent across reboot. These parameters can be changed or over-
ridden by the command line options of -i, -o, and -a.
The different sections in the /etc/intctl.conf configuration file are described as follows:
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. The
weight 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 (that is, a large weight number) corresponds to more interrupt
load on the CPU.
The -o drv:driver_name:weight option can be used to override an existing driver weight or to
specify new driver weights temporarily.
HP-UX 11i Version 3: September 2010 − 7 − Hewlett-Packard Company 7