Re: RFC: IRQ affinity (aka interrupt routing)

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

(2014/08/21 17:05), Manuel Bouyer wrote:
> On a x86 server here:
> interrupt                                     total     rate
> TLB shootdown                             788900019      295
> cpu0 timer                                265870470       99
> ioapic0 pin 9                                     0        0
> ioapic0 pin 16                           1491906220      557
> ioapic1 pin 14                            153885893       57
> ioapic0 pin 17                                 2731        0
> ioapic3 pin 0                                    13        0
> ioapic3 pin 1                                    14        0
> ioapic0 pin 21                                  789        0
> ioapic0 pin 20                             15285596        5
> ioapic0 pin 14                                    1        0
> ioapic0 pin 4                                     0        0
> ioapic0 pin 3                                   353        0
> Total                                    2715852099     1015
>
> Notice we have both 'ioapic0 pin 14' and 'ioapic1 pin 14',
> what number would be used for intrctl in this case ?

Currently intrctl use "14" for both 'ioapic0' and 'ioapic1', this is
a bug...
I fix it as intrctl use "14" for 'ioapic0' on the other hand "38" for
'ioapic1'. "38" for 'ioapic1' is defined following
    14 (pin number) + 24 * 1 (offset for secondary ioapic)
   # in the case of 'ioapic3 pin 1', 1 + 24 * 3 = 73 is used by intrctl
An ioapic has 24 pins, so I think adding 24 can avoid duplication. However
it may be not so good. I consider a little more about this implementation.

By the way, I haven't seen ioapic*3*. Could you tell me your machine's
model number?

Thanks,

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Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>