RE: ACPI patches updated (20030714)

From: Mikael Pettersson (
Date: Wed Jul 16 2003 - 04:47:08 EST

On Tue, 15 Jul 2003 12:11:17 -0700, "Grover, Andrew" wrote:
>> From: Mikael Pettersson []
>> I would like to see HT_ONLY generalized to parsing the MADT for
>> I/O-APICs. The problem I have is that some mainboards, like my
>> i850 ASUS P4T-E, have I/O-APICs but no MP tables. The only way for
>> the Linux kernel to discover the I/O-APICs on these mainboard is
>> through MADT parsing.
>> However, this currently requires me to enable all of ACPI, which
>> I don't need or want for many reasons, including code bloat and
>> behavioural side-effects.
>> Replacing "HT_ONLY" with "MADT_PARSING_ONLY" would be ideal, IMO.
>This won't help you. If you have *no* MPS tables, then you need ACPI
>(and specifically the ability to execute the _PRT control methods) for
>interrupt routing information, in addition to ioapic and local apic
>(CPU) enumeration. If this wasn't the case, I'm sure someone would have
>implemented ioapic MADT enumeration code long ago.


>Also, nothing is going to fundamentally change the size of the ACPI code
>(but we do keep chipping away at it, as evidenced by the dynamic SDT
>patch, -Os, etc.) but I'd like to hear more about the behavioral
>side-effects you'd mentioned, with an eye towards fixing them.

The main side-effect _was_ seeing the interpreter being run.
I didn't know it was needed for figuring out IRQ routing.

Concerning code size, the 70K number in ACPI's Kconfig help is
out of date. A minimal ACPI (all user-selectable suboptions
disabled) adds 145K to my 2.6.0-test1 kernel.

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This archive was generated by hypermail 2b29 : Wed Jul 23 2003 - 22:00:23 EST