Messages in this thread | | | Date | Mon, 26 May 2003 19:44:19 -0700 | From | William Lee Irwin III <> | Subject | Re: userspace irq balancer |
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On Mon, 26 May 2003, William Lee Irwin III wrote: >> The number of interrupt sources on a system ends up scaling this up to >> numerous IO-APIC RTE reprograms and ioapic_lock acquisitions per-second >> (granted, with a 5s timeout between reprogramming storms) where it >> competes against IO-APIC interrupt acknowledgements. >> Making the lock per- IO-APIC would at least put a bound on the number >> of competitors mutually interfering with each other, but a tighter >> bound on the amount of work than NR_IRQS would be more useful than that.
On Mon, May 26, 2003 at 10:15:23PM -0400, Zwane Mwaikambo wrote: > Ok there are 16 IOAPICs on an 8quad, but really if we start banging on > that lock someone is doing way too much hardware access...
It's done to acknowledge every interrupt. Also, there is additional cost associated with bouncing the lock's cacheline.
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