Messages in this thread |  | | From | James Cleverdon <> | Subject | Re: [PATCH] 2.5.31 Summit NUMA patch with dynamic IRQ balancing | Date | Sun, 25 Aug 2002 18:59:29 -0700 |
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On Friday 23 August 2002 05:29 pm, Grover, Andrew wrote: > > From: James Cleverdon [mailto:jamesclv@us.ibm.com] > > > > > This should be moved to acpi.h > > > > Will be, once I'm sure this is the right way to go. As > > mentioned earlier, I'm > > having ACPI problems that seem to imply ACPI isn't building > > the full IRQ > > table. In 2.4 we could let MPS do this. Maybe 2.5 will need > > to revert to > > that behavior. > > What happens when you use the FULL ACPI support? I suspect that you really > do want the interpreter, in order to evaluate _PRTs properly. > > ISTR that the reason you are thinking that ACPI only is programming some of > the ioapic entries is because whatever is printing them is looking at the > mp_irqs array. Which is MPS specific. So ACPI doesn't bother filling it all > in. :) > > Is that a bug? Should ACPI fill it in completely, or maybe not at all? > Don't know. But it is strictly unnecessary. > > Regards -- Andy
Bingo! With full ACPI turned on, the system does indeed boot. The extra I/O APIC entries are being programmed from the PRT.
(Call chain is: pci_acpi_init --> acpi_pci_irq_init --> mp_parse_prt --> io_apic_set_pci_routing)
So, given that quite a number of our customers would like to run with hyperthreading turned on, but do not want full ACPI, what is the right thing to do in the HT-only case? Add extra code to process the PRT? Fall back on MPS's IRQ records? Something else entirely?
-- James Cleverdon IBM xSeries Linux Solutions {jamesclv(Unix, preferred), cleverdj(Notes)} at us dot ibm dot com
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