From: Arnaldo Carvalho de Melo <acme@redhat.com>
To: Jeba Anandhan <jeba.anandhan@vaioni.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>,
netdev@vger.kernel.org, matthew.hattersley@vaioni.com
Subject: Re: SMP code / network stack
Date: Thu, 10 Jan 2008 15:46:57 -0200 [thread overview]
Message-ID: <20080110174657.GL22437@ghostprotocols.net> (raw)
In-Reply-To: <1199978819.29856.43.camel@vglwks010.vgl2.office.vaioni.com>
Em Thu, Jan 10, 2008 at 03:26:59PM +0000, Jeba Anandhan escreveu:
> Hi Eric,
> Thanks for the reply. I have one more doubt. For example, if we have 2
> processor and 4 ethernet cards. Only CPU0 does all work through 8 cards.
> If we set the affinity to each ethernet card as CPU number, will it be
> efficient?.
>
> Will this be default behavior?
>
> # cat /proc/interrupts
> CPU0 CPU1
> 0: 11472559 74291833 IO-APIC-edge timer
> 2: 0 0 XT-PIC cascade
> 8: 0 1 IO-APIC-edge rtc
> 81: 0 0 IO-APIC-level ohci_hcd
> 97: 1830022231 847 IO-APIC-level ehci_hcd, eth0
> 97: 3830012232 847 IO-APIC-level ehci_hcd, eth1
> 97: 5830052231 847 IO-APIC-level ehci_hcd, eth2
> 97: 6830032213 847 IO-APIC-level ehci_hcd, eth3
> #sleep 10
>
> # cat /proc/interrupts
> CPU0 CPU1
> 0: 11472559 74291833 IO-APIC-edge timer
> 2: 0 0 XT-PIC cascade
> 8: 0 1 IO-APIC-edge rtc
> 81: 0 0 IO-APIC-level ohci_hcd
> 97: 2031409801 847 IO-APIC-level ehci_hcd, eth0
> 97: 4813981390 847 IO-APIC-level ehci_hcd, eth1
> 97: 7123982139 847 IO-APIC-level ehci_hcd, eth2
> 97: 8030193010 847 IO-APIC-level ehci_hcd, eth3
>
>
> Instead of the above mentioned ,if we set the affinity for eth2 and
> eth3.
> the output will be
>
> # cat /proc/interrupts
> CPU0 CPU1
> 0: 11472559 74291833 IO-APIC-edge timer
> 2: 0 0 XT-PIC cascade
> 8: 0 1 IO-APIC-edge rtc
> 81: 0 0 IO-APIC-level ohci_hcd
> 97: 1830022231 847 IO-APIC-level ehci_hcd, eth0
> 97: 3830012232 847 IO-APIC-level ehci_hcd, eth1
> 97: 5830052231 923 IO-APIC-level ehci_hcd, eth2
> 97: 6830032213 1230 IO-APIC-level ehci_hcd, eth3
> #sleep 10
>
> # cat /proc/interrupts
> CPU0 CPU1
> 0: 11472559 74291833 IO-APIC-edge timer
> 2: 0 0 XT-PIC cascade
> 8: 0 1 IO-APIC-edge rtc
> 81: 0 0 IO-APIC-level ohci_hcd
> 97: 2300022231 847 IO-APIC-level ehci_hcd, eth0
> 97: 4010212232 847 IO-APIC-level ehci_hcd, eth1
> 97: 5830052231 1847 IO-APIC-level ehci_hcd, eth2
> 97: 6830032213 2337 IO-APIC-level ehci_hcd, eth3
>
> In this case, will the performance improves?.
ps ax | grep irqbalance
tells what?
If it is enabled please try:
service irqbalance stop
chkconfig irqbalance off
Then reset the smp_affinity entries to ff so and try again.
http://www.irqbalance.org/
- Arnaldo
next prev parent reply other threads:[~2008-01-10 17:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-10 14:05 SMP code / network stack Jeba Anandhan
2008-01-10 14:45 ` Eric Dumazet
2008-01-10 15:26 ` Jeba Anandhan
2008-01-10 17:46 ` Arnaldo Carvalho de Melo [this message]
2008-01-10 18:31 ` Kok, Auke
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