Re: [PATCH] x86: remove update_apic from x86_quirks

From: Ingo Molnar
Date: Thu Feb 26 2009 - 06:41:25 EST



* Yinghai Lu <yinghai@xxxxxxxxxx> wrote:

> Ingo Molnar wrote:
> > except that it doesnt build:
> >
> > arch/x86/kernel/built-in.o:(.data+0x8c08): undefined reference to `wakeup_secondary_cpu_via_init'
> > arch/x86/kernel/built-in.o:(.data+0x8d68): undefined reference to `wakeup_secondary_cpu_via_init'
> > arch/x86/kernel/built-in.o:(.data+0x8ec8): undefined reference to `wakeup_secondary_cpu_via_init'
> > arch/x86/kernel/built-in.o:(.data+0x9038): undefined reference to `wakeup_secondary_cpu_via_init'
> >
>
> .config?

There's no need for a config :)

When introducing a widely used symbol as
wakeup_secondary_cpu_via_init(), the first thing to check is to
make sure it's built in widely enough:

$ git grep wakeup_secondary_cpu_via_init

arch/x86/include/asm/apic.h:extern int wakeup_secondary_cpu_via_init(int apicid, unsigned long start_eip);
arch/x86/kernel/apic/apic_flat_64.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/apic/apic_flat_64.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/apic/bigsmp_32.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/apic/es7000_32.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/apic/probe_32.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/apic/summit_32.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/apic/x2apic_cluster.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/apic/x2apic_phys.c: .wakeup_cpu = wakeup_secondary_cpu_via_init,
arch/x86/kernel/smpboot.c:wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)

as you can see it's defined in arch/x86/kernel/smpboot.c -
which, as its name already tells us, is only built on SMP.

There's other usage though, like
arch/x86/kernel/apic/probe_32.c, which is built on
CONFIG_X86_LOCAL_APIC=y, which can be enabled on !SMP as well.

Since on SMP we are not likely to boot other CPUs via
apic->wakeup_cpu(), i suspect we need a !SMP inline for
wakeup_secondary_cpu_via_init()?

Ingo
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