irqbalance Man page



irqbalance – distribute hardware interrupts across processors on a mul‐
tiprocessor system




The purpose of irqbalance is to distribute hardware interrupts across
processors on a multiprocessor system in order to increase performance.


-o, –oneshot
Causes irqbalance to be run once, after which the daemon exits.

-d, –debug
Causes irqbalance to print extra debug information. Implies

-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= Set the threshold at which we attempt to move a CPU into power‐
save mode If more than 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=
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

This allows a user to specify the cache level at which irqbal‐
ance 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 set‐
ting 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 –deep‐

The default value for deepestcache is 2.

-l, –policyscript=