IRQBALANCE(1)irqbalanceIRQBALANCE(1)NAMEirqbalance - distribute hardware interrupts across processors on a mul‐
tiprocessor system
SYNOPSISirqbalanceDESCRIPTION
The purpose of irqbalance is distribute hardware interrupts across pro‐
cessors on a multiprocessor system in order to increase performance.
OPTIONS--oneshot
Causes irqbalance to be run once, after which the daemon exits
--debug
Causes irqbalance to print extra debug information. Implies
--foreground
--foreground
Causes irqbalance to run in the foreground (without --debug)
--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
affintiy hint
ignore irq affinity hint value is completely ignored
--powerthresh=<threshold>
Set the threshold at which we attempt to move a cpu into power‐
save 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.
--banirq=<irqnum>
Add the specified irq list 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
--banscript=<script>
Execute the specified script for each irq that is discovered,
passing the sysfs path to the associated device as the first
argument, and the irq vector as the second. An exit value of 0
tells irqbalance that this interrupt should balanced and managed
as a normal irq, while a non-zero exit code indicates this irq
should be ignored by irqbalance completely (see --banirq above).
Use of this script provides users the ability to dynamically
select which irqs get exluded from balancing, and provides an
opportunity for manual affinity setting in one single code
point.
--pid=<file>
Have irqbalance write its process id to the specified file. By
default no pidfile is written. The written pidfile is automati‐
cally unlinked when irqbalance exits.
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
http://code.google.com/p/irqbalance
Linux Dec 2006 IRQBALANCE(1)