* 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why?
@ 2008-12-30 12:26 Justin Piszcz
2009-01-02 22:23 ` Arjan van de Ven
2009-01-02 22:35 ` Kyle McMartin
0 siblings, 2 replies; 6+ messages in thread
From: Justin Piszcz @ 2008-12-30 12:26 UTC (permalink / raw)
To: linux-kernel, arjan
(same on both x86 and x86_64):
# cat /etc/default/irqbalance
#Configuration for the irqbalance daemon
#Should irqbalance be enabled?
ENABLED=1
#Balance the IRQs only once?
ONESHOT="0"
========
my x86 system:
========
# /etc/init.d/irqbalance start
Starting SMP IRQ Balancer: irqbalance.
# ps auxww | grep -i irqbalance
root 4570 0.0 0.0 2536 436 ? Ss 07:07 0:00 /usr/sbin/irqbalance
# sleep 300; ps auxww | grep -i irqbalance
#
=========
On my x86_64 systems:
=========
$ ps auxww | grep -i irqbalance
root 2769 0.0 0.0 8828 492 ? Ss Dec27 0:06 /usr/sbin/irqbalance
$ ps auxww | grep -i irqbalance
root 2918 0.0 0.0 8828 520 ? Ss Dec22 0:18 /usr/sbin/irqbalance
Is there a bug on x86?
Justin.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why?
2008-12-30 12:26 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why? Justin Piszcz
@ 2009-01-02 22:23 ` Arjan van de Ven
2009-01-03 0:32 ` Justin Piszcz
2009-01-02 22:35 ` Kyle McMartin
1 sibling, 1 reply; 6+ messages in thread
From: Arjan van de Ven @ 2009-01-02 22:23 UTC (permalink / raw)
To: Justin Piszcz; +Cc: linux-kernel
Justin Piszcz wrote:
> (same on both x86 and x86_64):
> # cat /etc/default/irqbalance
> #Configuration for the irqbalance daemon
>
> #Should irqbalance be enabled?
> ENABLED=1
> #Balance the IRQs only once?
> ONESHOT="0"
which version of irqbalance is this?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why?
2008-12-30 12:26 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why? Justin Piszcz
2009-01-02 22:23 ` Arjan van de Ven
@ 2009-01-02 22:35 ` Kyle McMartin
1 sibling, 0 replies; 6+ messages in thread
From: Kyle McMartin @ 2009-01-02 22:35 UTC (permalink / raw)
To: Justin Piszcz; +Cc: linux-kernel, arjan
On Tue, Dec 30, 2008 at 07:26:30AM -0500, Justin Piszcz wrote:
> (same on both x86 and x86_64):
> # cat /etc/default/irqbalance
> #Configuration for the irqbalance daemon
>
> #Should irqbalance be enabled?
> ENABLED=1
> #Balance the IRQs only once?
> ONESHOT="0"
>
If there is only one cache domain, ie: one physical cpu socket with two
cores sharing a cache, then irqbalance will return after the initial
balance since it would be pointless to continue running. (It forces
itself into oneshot mode.)
regards, Kyle
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why?
2009-01-02 22:23 ` Arjan van de Ven
@ 2009-01-03 0:32 ` Justin Piszcz
2009-01-03 1:08 ` Kyle McMartin
0 siblings, 1 reply; 6+ messages in thread
From: Justin Piszcz @ 2009-01-03 0:32 UTC (permalink / raw)
To: Arjan van de Ven; +Cc: linux-kernel, Kyle McMartin
On Fri, 2 Jan 2009, Arjan van de Ven wrote:
> Justin Piszcz wrote:
>> (same on both x86 and x86_64):
>> # cat /etc/default/irqbalance
>> #Configuration for the irqbalance daemon
>>
>> #Should irqbalance be enabled?
>> ENABLED=1
>> #Balance the IRQs only once?
>> ONESHOT="0"
>
>
> which version of irqbalance is this?
>
$ dpkg -l | grep -i irqbalance
ii irqbalance 0.55-2.4 Daemon to balance interrupts for SMP systems
Kyle stated:
> If there is only one cache domain, ie: one physical cpu socket with two
> cores sharing a cache, then irqbalance will return after the initial
> balance since it would be pointless to continue running. (It forces
> itself into oneshot mode.)
The CPU = E6700 so yep, so if there is one physical socket with 4 cores it
keeps? For it to keep and not oneshot you need > 2 cores?
Justin.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why?
2009-01-03 0:32 ` Justin Piszcz
@ 2009-01-03 1:08 ` Kyle McMartin
2009-01-03 1:11 ` Justin Piszcz
0 siblings, 1 reply; 6+ messages in thread
From: Kyle McMartin @ 2009-01-03 1:08 UTC (permalink / raw)
To: Justin Piszcz; +Cc: Arjan van de Ven, linux-kernel, Kyle McMartin
On Fri, Jan 02, 2009 at 07:32:21PM -0500, Justin Piszcz wrote:
> The CPU = E6700 so yep, so if there is one physical socket with 4 cores it
> keeps? For it to keep and not oneshot you need > 2 cores?
>
It depends... if your 4-core is laid out with four cores sharing one
external cache, then it will terminate, if, say you had 4 cores with
each pair sharing a cache (so two external caches) then it would
continue as a daemon. (If you had 2 sockets with a processor in each
one, it would continue running as well no matter how many cores on
each.)
If you run irqbalance --debug, it will show you the topology it detects.
If you have multiple cache domains, and it is still exiting, then we
have a bug. :)
cheers, Kyle
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why?
2009-01-03 1:08 ` Kyle McMartin
@ 2009-01-03 1:11 ` Justin Piszcz
0 siblings, 0 replies; 6+ messages in thread
From: Justin Piszcz @ 2009-01-03 1:11 UTC (permalink / raw)
To: Kyle McMartin; +Cc: Arjan van de Ven, linux-kernel
On Fri, 2 Jan 2009, Kyle McMartin wrote:
> On Fri, Jan 02, 2009 at 07:32:21PM -0500, Justin Piszcz wrote:
>> The CPU = E6700 so yep, so if there is one physical socket with 4 cores it
>> keeps? For it to keep and not oneshot you need > 2 cores?
>>
>
> It depends... if your 4-core is laid out with four cores sharing one
> external cache, then it will terminate, if, say you had 4 cores with
> each pair sharing a cache (so two external caches) then it would
> continue as a daemon. (If you had 2 sockets with a processor in each
> one, it would continue running as well no matter how many cores on
> each.)
>
> If you run irqbalance --debug, it will show you the topology it detects.
> If you have multiple cache domains, and it is still exiting, then we
> have a bug. :)
>
> cheers, Kyle
>
Looks correct, just a single cache domain on this host-- thanks.
# irqbalance --debug
Package 0: cpu mask is 00000003 (workload 0)
Cache domain 0: cpu mask is 00000003 (workload 0)
CPU number 0 (workload 0)
CPU number 1 (workload 0)
Interrupt 315 (class ethernet) has workload 20
Interrupt 0 (class timer) has workload 0
Interrupt 314 (class storage) has workload 11
Interrupt 16 (class legacy) has workload 216
Interrupt 17 (class legacy) has workload 122
Interrupt 23 (class legacy) has workload 26
Interrupt 19 (class legacy) has workload 18
Interrupt 1 (class legacy) has workload 1
Interrupt 18 (class legacy) has workload 0
Interrupt 9 (class legacy) has workload 0
Interrupt 6 (class legacy) has workload 0
-----------------------------------------------------------------------------
IRQ delta is 3963
Package 0: cpu mask is 00000003 (workload 2474)
Cache domain 0: cpu mask is 00000003 (workload 2474)
CPU number 0 (workload 1343)
Interrupt 314 (storage/13)
Interrupt 16 (legacy/1080)
Interrupt 19 (legacy/245)
Interrupt 18 (legacy/0)
Interrupt 6 (legacy/0)
CPU number 1 (workload 1131)
Interrupt 315 (ethernet/132)
Interrupt 17 (legacy/689)
Interrupt 23 (legacy/291)
Interrupt 1 (legacy/14)
Interrupt 9 (legacy/0)
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-01-03 1:11 UTC | newest]
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2008-12-30 12:26 2.6.27/2.6.28: irqbalance dies shortly after starting the daemon on x86 but not x86_64, why? Justin Piszcz
2009-01-02 22:23 ` Arjan van de Ven
2009-01-03 0:32 ` Justin Piszcz
2009-01-03 1:08 ` Kyle McMartin
2009-01-03 1:11 ` Justin Piszcz
2009-01-02 22:35 ` Kyle McMartin
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