Messages in this thread | | | Date | Thu, 10 Jan 2008 11:01:30 -0800 | From | "Kok, Auke" <> | Subject | Re: questions on NAPI processing latency and dropped network packets |
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Rick Jones wrote: >> 1) Interrupts are being processed on both cpus: >> >> root@base0-0-0-13-0-11-1:/root> cat /proc/interrupts >> CPU0 CPU1 >> 30: 1703756 4530785 U3-MPIC Level eth0 > > IIRC none of the e1000 driven cards are multi-queue
the pci-express variants are, but the functionality is almost always disabled (and relatively new anyway).
even with multiqueue, you can still have only a single irq line (which defeats the purpose of course mostly).
>, so while the above > shows that interrupts from eth0 have been processed on both CPUs at > various points in the past, it doesn't necessarily mean that they are > being processed on both CPUs at the same time right?
never will, an irq can only be processed on one cpu at a time anyway, obviously the irq here has been migrated ONCE from one of the cpu's to the other. unfortunately you can't see from /proc/interrupts whether this happens frequently or not, or how many times it happened before.
Auke
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