Provided by: irqbalance_1.1.0-2ubuntu1_amd64 
NAME
irqbalance - distribute hardware interrupts across processors on a multiprocessor system
SYNOPSIS
irqbalance
DESCRIPTION
The purpose of irqbalance is to distribute hardware interrupts across processors on a multiprocessor
system in order to increase performance.
OPTIONS
-o, --oneshot
Causes irqbalance to be run once, after which the daemon exits.
-d, --debug
Causes irqbalance to print extra debug information. Implies --foreground.
-f, --foreground
Causes irqbalance to run in the foreground (without --debug).
-j, --journal
Enables log output optimized for systemd-journal.
-h, --hintpolicy=[exact | subset | ignore]
Set the policy for how IRQ kernel affinity hinting is treated. Can be one of:
exact IRQ affinity hint is applied unilaterally and never violated.
subset IRQ is balanced, but the assigned object will be a subset of the affinity hint.
ignore IRQ affinity hint value is completely ignored.
The default value for hintpolicy is ignore.
-p, --powerthresh=<threshold>
Set the threshold at which we attempt to move a CPU into powersave mode If more than <threshold>
CPUs are more than 1 standard deviation below the average CPU softirq workload, and no CPUs are
more than 1 standard deviation above (and have more than 1 IRQ assigned to them), attempt to place
1 CPU in powersave mode. In powersave mode, a CPU will not have any IRQs balanced to it, in an
effort to prevent that CPU from waking up without need.
-i, --banirq=<irqnum>
Add the specified IRQ to the set of banned IRQs. irqbalance will not affect the affinity of any
IRQs on the banned list, allowing them to be specified manually. This option is addative and can
be specified multiple times. For example to ban IRQs 43 and 44 from balancing, use the following
command line: irqbalance --banirq=43 --banirq=44
--deepestcache=<integer>
This allows a user to specify the cache level at which irqbalance partitions cache domains.
Specifying a deeper cache may allow a greater degree of flexibility for irqbalance to assign IRQ
affinity to achieve greater performance increases, but setting a cache depth too large on some
systems (specifically where all CPUs on a system share the deepest cache level), will cause
irqbalance to see balancing as unnecessary. irqbalance --deepestcache=2
The default value for deepestcache is 2.
-l, --policyscript=<script>
When specified, the referenced script will execute once for each discovered IRQ, with the sysfs
device path and IRQ number passed as arguments. Note that the device path argument will point to
the parent directory from which the IRQ attributes directory may be directly opened. The script
may specify zero or more key=value pairs that will guide irqbalance in the management of that IRQ.
Key=value pairs are printed by the script on stdout and will be captured and interpreted by
irqbalance. Irqbalance expects a zero exit code from the provided utility. Recognized key=value
pairs are:
ban=[true | false]
Directs irqbalance to exclude the passed in IRQ from balancing.
balance_level=[none | package | cache | core]
This allows a user to override the balance level of a given IRQ. By default the balance level is
determined automatically based on the pci device class of the device that owns the IRQ.
numa_node=<integer>
This allows a user to override the NUMA node that sysfs indicates a given device IRQ is local to.
Often, systems will not specify this information in ACPI, and as a result devices are considered
equidistant from all NUMA nodes in a system. This option allows for that hardware provided
information to be overridden, so that irqbalance can bias IRQ affinity for these devices toward
its most local node. Note that specifying a -1 here forces irqbalance to consider an interrupt
from a device to be equidistant from all nodes.
hintpolicy=[exact | subset | ignore ]
This allows a user to override the globally set hintpolicy for a given irq. Use is identical to
the --hintpolicy setting, but applied per irq
-s, --pid=<file>
Have irqbalance write its process id to the specified file. By default no pidfile is written.
The written pidfile is automatically unlinked when irqbalance exits. It is ignored when used with
--debug or --foreground.
-t, --interval=<time>
Set the measurement time for irqbalance. irqbalance will sleep for <time> seconds between samples
of the irq load on the system cpus. Defaults to 10.
ENVIRONMENT VARIABLES
IRQBALANCE_ONESHOT
Same as --oneshot.
IRQBALANCE_DEBUG
Same as --debug.
IRQBALANCE_BANNED_CPUS
Provides a mask of CPUs which irqbalance should ignore and never assign interrupts to.
SIGNALS
SIGHUP Forces a rescan of the available IRQs and system topology.
Homepage
https://github.com/Irqbalance/irqbalance