Re: Request: increase in PCI bus limit

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>
> I'm working at a customer site with custom hardware. The 2.4.0 series
> kernel almost works out of the box, but the machine has 52 PCI busses.
> Plans are to produce a 4-way box which would have over 80 PCI busses. The
> file include/asm-i386/mpspec.h allocates space for 32 busses in the
> definition of the macro MAX_MP_BUSSES.
>

How long is the MP structure?
smp_scan_config() reserves only 4 kB:

        reserve_bootmem(mpf->mpf_physptr, PAGE_SIZE);

reserving the actual size (mpf->mpf_physptr->mpc_length) could be
tricky.

It should be possible to dynamically allocate the memory for the busses:
It's not yet possible (smp_read_mpc() is called at a very early stage,
before kmalloc is initialized), but we must move it to a later stage
anyway:
some Compaq bios version need ioremap() in smp_read_mpc(), and we should
parse the ACPI tables for APIC descriptors (MADT, ia64 does that
already).

I'll add it to my TODO list.

--
	Manfred
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• Next message: Marcelo Tosatti: "Re: [PATCH] vma limited swapin readahead"
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• Maybe in reply to: Christopher Neufeld: "Request: increase in PCI bus limit"
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