Messages in this thread | | | Date | Fri, 3 Mar 2000 06:44:13 -0700 | From | yodaiken@fsmlabs ... | Subject | Re: new IRQ scalability changes in 2.3.48 |
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On Fri, Mar 03, 2000 at 03:25:23PM +0100, Ingo Molnar wrote: > check out the fast path of level-triggered PCI IRQs: > > do_IRQ() > mask_and_ack_level_ioapic_irq: empty! > ->handler() > end_level_ioapic_irq: a fast local-APIC write > > no lowlevel spinlock taken. This is actually the case where the IOAPIC IRQ > hardware turned out to be very sane. The borken edge-triggered case is > nicely isolated.
I have not looked at the APIC docs recently, but doesn't this block irqs during the "fast path" ?
Since we need a spin lock anyways in doIRQ, I still don't get how this makes things any better.
-- --------------------------------------------------------- Victor Yodaiken FSMLabs: www.fsmlabs.com www.rtlinux.com FSMLabs is a servicemark and a service of VJY Associates L.L.C, New Mexico.
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