linux-kernel - x86_32_early_logical_apicid() -> one warning per CPU on late-determined BIGSMP systems

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Message-Id: <4E43EBDF0200007800050CA7@nat28.tlf.novell.com>
Date:	Thu, 11 Aug 2011 13:49:03 +0100
From:	"Jan Beulich" <JBeulich@...ell.com>
To:	<tj@...nel.org>
Cc:	<mingo@...e.hu>, <linux-kernel@...r.kernel.org>
Subject: x86_32_early_logical_apicid() -> one warning per CPU on
	 late-determined BIGSMP systems

Tejun,

with generic_processor_info() getting run before generic_bigsmp_probe(),
the values obtained by the former though apic->x86_32_early_logical_apicid()
(still pointing to default_x86_32_early_logical_apicid() at that time) and
stored into early_per_cpu(x86_cpu_to_logical_apicid, cpu) can't possibly
match the ones obtained by setup_local_APIC() (since only at this point
apic->x86_32_early_logical_apicid() points to bigsmp_early_logical_apicid()),
thus causing the warning there to generally trigger on each CPU.

Except for removing the warning, all other possible solutions to this that
I can think of seem ugly to me (i.e. somehow re-initializing
x86_cpu_to_logical_apicid for all CPUs), but I wonder why setting up
x86_cpu_to_logical_apicid needs to be done this early if prior to
setup_local_APIC() doing it a second time the value can't be used for
anything anyway (because it could validly be BAD_APICID). If there
aren't any future plans (honestly, I can't really make much sense of
commit acb8bc09c6185e4d3d582d0076aaa6a89f19d8c5's comment),
perhaps x86_32_early_logical_apicid() could get removed again?

Jan

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