intrbald(1M)intrbald(1M)NAMEintrbald - daemon for balancing interrupts
Balancing interrupts is a process which distributes interrupts across
the available CPUs in an optimal fashion. This action is performed by
Performing frequent CPU migrations between system partitions may
require you to perform periodic balancing of interrupts. This is espe‐
cially true with systems that use WLM (Workload Manager), iCAP (Instant
Capacity), and vPars (Virtual Partitions) products. If the frequency
of CPU migration is high, then balancing of interrupts should be per‐
formed more frequently.
The daemon monitors the system for imbalance in interrupt distribution.
If an imbalance is detected after the specified interval executes to
balance the interrupt distribution. uses the parameters from the con‐
figuration file for balancing the interrupts. For more information
about the command, see intctl(1M) and the configuration file.
The daemon is started from the general purpose sequencer script (see
rc(1M)), at run level 2 and is killed at run level 1. By default, the
daemon is not enabled. The daemon configuration file must be edited
and the parameter set to in order to enable running the daemon. After
setting to for the first time, you can start the daemon manually by
executing the script Otherwise, the daemon will automatically start the
next time the system is restarted.
Any actions performed by the daemon are logged in and details of inter‐
rupt migrations performed will be logged in the file
recognizes the following options:
Instructs the running daemon to reexamine the configuration file
If the parameter has been updated, then the running dae‐
mon uses the new value. If the parameter is set to then
the running daemon stops executing.
The daemon checks if the system requires any balancing of interrupts
after interval seconds; the valid range is 5 seconds to
seconds (see limits(5)).
This value can also be specified persistently in the
configuration file by setting the parameter.
The default value is 60 seconds.
Setting this value too small can cause unnecessary
Gracefully kills the running daemon.
intrbald rc Configuration File
is the configuration file.
The following parameters can be persistently specified in this configu‐
Specifies if the daemon should be started automatically during the sys‐
tem bootup process by the script. The daemon will only be started
automatically if this parameter is set to
NOTE: This value is by default. Before using the daemon, needs
to be changed to in the file. Then the daemon needs to be
started, either manually by running or it will be started auto‐
matically at next boot via the script.
The daemon checks if the system requires any
interrupt balancing after this interval. The interval is speci‐
fied in seconds; the valid range is 5 seconds to seconds (see
limits(5)). The default is 60 seconds.
Setting this value too small could cause unnecessary interrupt
Exit values are:
An error condition occurred.
The command can be executed only by the superuser. This command should
be used only by performance analysts for performance tuning purposes.
If the interrupts are not redistributed properly, a possible decrease
in overall system performance can occur. Some processors can become
overloaded while other processors will not be optimally utilized.
configuration file. See the section above.
start symbolic link.
kill symbolic link.
daemon log file.
SEE ALSOintctl(1M), ioscan(1M), rc(1M), limits(5).