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Date:      Sun, 4 Sep 2016 20:14:07 +0300
From:      Andriy Gapon <>
To:        Konstantin Belousov <>
Cc:        Slawa Olhovchenkov <>,
Subject:   Re: X2APIC support
Message-ID:  <>
In-Reply-To: <>
References:  <> <> <> <> <> <> <> <> <>

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On 04/09/2016 19:29, Konstantin Belousov wrote:
> This is possible, of course.  But it would not affect "SMP: Added CPU ..."
> lines.

Well, looking at the code it seems that only if mptable is used, then those
lines are expected to correctly identify a BSP.  With MADT there is no
information to identify the BSP and that is supposed to happen in cpu_mp_start().

static void
madt_add_cpu(u_int acpi_id, u_int apic_id, u_int flags)
        struct lapic_info *la;

         * The MADT does not include a BSP flag, so we have to let the
         * MP code figure out which CPU is the BSP on its own.

In other words, those "SMP: Added CPU ..." are truly a cosmetic issue.
And it's my guess (just a guess) that BSP LAPIC ID is incorrect in the
problematic configuration.

Andriy Gapon

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