On Thu, Nov 13, 2008 at 08:56:31AM -0800, Jeremy Chadwick wrote: > Regarding "it means you can still get interrupt sharing", I'd like to > hear more about why/how that's possible with a system sporting at least > one I/O APIC.
You still have a limited number of interrupt lines. Many non-highend mainboards have 4 or 8 interrupt lines. You often have more than 8 PCI devices that want interrupts (e.g. VGA, audio, 3 USB controllers, 1 EHCI contoller and the SATA controller are enough to consume all lines). As soon as you now add a new network devices, you end up sharing PCI lines. The IO-APIC wiring is also often fixed, so it can't be controlled by software. Joerg _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
