Re: Question about isolating CPU's

Hi,

Le mer. 13 avril 2016 à 23:26, Paolo Mantegazza 
<[email protected]> a écrit :
> Sorry, i clicked the wrong button.
> I'm assuming you are referring to irq affinities.
> At the moment I've none ready,  I usually write one for a specific 
> machine I'm working on.
> It is simple and requires just these steps:
> - "cat /proc/interrupts" to get the interrupts of interest
> - writing for each of them "echo affinity_mask 
> >/proc/irq/irq_number_of_interest/smp_affinity"
> Usually my scripts are just a list of the above command and made 
> executable, with the mask containing the bits of those cpus that are 
> not isolated for RTAI.
> That's all.

On fedora/redhat, there is a irqbalance service that could help you 
setup irq affinities.

The configuration file of this service is in /etc/sysconfig/irqbalance. 
For example, if you want to isolate all the cpus except te first one, 
it should have the following content:

# irqbalance is a daemon process that distributes interrupts across
# CPUS on SMP systems. The default is to rebalance once every 10
# seconds. This is the environment file that is specified to systemd 
via the
# EnvironmentFile key in the service unit file (or via whatever method 
the init
# system you're using has.
#
# ONESHOT=yes
# after starting, wait for a minute, then look at the interrupt
# load and balance it once; after balancing exit and do not change
# it again.
IRQBALANCE_ONESHOT=yes

#
# IRQBALANCE_BANNED_CPUS
# 64 bit bitmask which allows you to indicate which cpu's should
# be skipped when reblancing irqs. Cpu numbers which have their
# corresponding bits set to one in this mask will not have any
# irq's assigned to them on rebalance
#
IRQBALANCE_BANNED_CPUS=fe

#
# IRQBALANCE_ARGS
# append any args here to the irqbalance daemon as documented in the 
man page
#
IRQBALANCE_ARGS=-d


Cheers,

	Emmanuel.

_______________________________________________
Rtai mailing list
[email protected]
https://mail.rtai.org/cgi-bin/mailman/listinfo/rtai