After updating to centos 4.3, I notice a failure in terminating irqbalance whenever i shutdown the system. Checking the services after the system reboot i see the error in irqbalance: "irqbalance dead but subsys locked" Can anyone tell me what irqbalance is and if it safe to disable it ? Why i dont see it in centos 4.2? Thanks in advance. Thai -------------------------------------------------- Where there's will, there's a way ________________________________________________________________________ Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.
On Tue, 2006-04-04 at 10:28 -0400, lnthai2002@aim.com wrote:
After updating to centos 4.3, I notice a failure in terminating irqbalance whenever i shutdown the system. Checking the services after the system reboot i see the error in irqbalance: "irqbalance dead but subsys locked" Can anyone tell me what irqbalance is
man irqbalance
returns "distribute hardware interrupts across processors on a multiprocessor system"
I haven't read the rest of the man page, so I can't/won't try to answer part 2.
and if it safe to disable it ? Why i dont see it in centos 4.2? Thanks in advance. Thai
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On 4/4/06, William L. Maltby BillsCentOS@triad.rr.com wrote:
On Tue, 2006-04-04 at 10:28 -0400, lnthai2002@aim.com wrote:
After updating to centos 4.3, I notice a failure in terminating irqbalance whenever i shutdown the system. Checking the services after the system reboot i see the error in irqbalance: "irqbalance dead but subsys locked" Can anyone tell me what irqbalance is
As the other person said it distrubutes IRQ's across multiple processors in an SMP system. You don't want to disable this as it will impact system performance. Just as a quick explanation, by default all of the IRQ's (the signals that let hardware devices notify the cpu and by extension device drivers know that they need servicing) end up on one processor (at least on Intel like architectures). The OS though can balance them across muliple processors which is typically more efficient (share the load sort of thing). I don't know the algorithms that irqbalance uses to distribute the IRQ's but it definately makes things more efficient. So again you don't want to disable this (unless your on a single processor machine, and then its a moot point; in this case disable away using chkconfig).
What I would sugest is filing a bugzilla report at bugzilla.redhat.com.
Cheers...james
if you don't have more than one cpu(HT doesn't count) then you don't need irqbalance. I have it disabled on all of my UP systems without negative effects.
James Olin Oden wrote:
On 4/4/06, William L. Maltby BillsCentOS@triad.rr.com wrote:
On Tue, 2006-04-04 at 10:28 -0400, lnthai2002@aim.com wrote:
After updating to centos 4.3, I notice a failure in terminating irqbalance whenever i shutdown the system. Checking the services after the system reboot i see the error in irqbalance: "irqbalance dead but subsys locked" Can anyone tell me what irqbalance is
As the other person said it distrubutes IRQ's across multiple processors in an SMP system. You don't want to disable this as it will impact system performance. Just as a quick explanation, by default all of the IRQ's (the signals that let hardware devices notify the cpu and by extension device drivers know that they need servicing) end up on one processor (at least on Intel like architectures). The OS though can balance them across muliple processors which is typically more efficient (share the load sort of thing). I don't know the algorithms that irqbalance uses to distribute the IRQ's but it definately makes things more efficient. So again you don't want to disable this (unless your on a single processor machine, and then its a moot point; in this case disable away using chkconfig).
What I would sugest is filing a bugzilla report at bugzilla.redhat.com.
Cheers...james _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
I get better performance when I disable it.
I put my PRI card interrupts on 1 CPU and my RAID controller, Eth, etc. on the other. This is a boost for my PRI cards. (digium cards for asterisk VOIP PBX) These cards produce 1000 interrupts per second.
irqbalance was reassigning the CPU for handling the interrupts on the PRI cards every few seconds. During the switch, I would drop a few interrupts.
On 4/4/06, Steven asterisk@tescogroup.com wrote:
I get better performance when I disable it.
I put my PRI card interrupts on 1 CPU and my RAID controller, Eth, etc. on the other. This is a boost for my PRI cards. (digium cards for asterisk VOIP PBX) These cards produce 1000 interrupts per second.
Sow how do you do that? Just curious...james
irqbalance was reassigning the CPU for handling the interrupts on the PRI cards every few seconds. During the switch, I would drop a few interrupts.
How does one note when the irq's are being changed for particular devices?
Thanks...james
cat /proc/interrupts is one indicator. It will show the interrupt count on each processor for each device. Run the command multiple times to see which column is incrementing the count. Only one column will change at a time per device, that is the CPU that is handling it.
cat /proc/irq/209/smp_affinity will also show you the processor for each irq. (209 in this case) echo 1 > /proc/irq/209/smp_affinity will set CPU0 to process those interrupts. echo 2 > /proc/irq/209/smp_affinity will set CPU1 to process those interrupts. echo 4 > /proc/irq/209/smp_affinity will set CPU2 to process those interrupts. echo 8 > /proc/irq/209/smp_affinity will set CPU3 to process those interrupts.
These settings only stick if you have disables irqbalance.
One other thing, You have to put the commands to set the CPU in a startup script like rc.local to reset them after a reboot.
On 4/5/06, Steve Snyder swsnyder@insightbb.com wrote:
On Wednesday 05 April 2006 11:27 am, Steven wrote:
One other thing, You have to put the commands to set the CPU in a startup script like rc.local to reset them after a reboot.
You can also configure the kernel to do IRQ balancing:
CONFIG_IRQBALANCE=y
Whats the advantage of that over using the daemon?
Thanks...james
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James Olin Oden -
lnthai2002＠aim.com -
Steve Snyder -
Steven -
William L. Maltby -
William Warren