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From: John Sigler <linux.kernel@free.fr>
To: linux-kernel@vger.kernel.org
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>
Subject: BIOS implementors disabling the LAPIC
Date: Tue, 31 Jul 2007 10:06:54 +0200	[thread overview]
Message-ID: <46AEED9E.1050904@free.fr> (raw)

I have several systems here where Linux tells me:
Local APIC disabled by BIOS -- you can enable it with "lapic"

As far as I understand, the Local APIC was integrated directly to the 
CPU 12-15 years ago. Why would a BIOS implementor choose to disable it?

(And what does it mean to "disable" the LAPIC?)

Note: the motherboard does not provide an IO-APIC.

I've ask the kernel to re-enable the LAPIC, and was able to use OProfile 
in hardware counter mode, i.e. it seems to work fine.

Regards.

             reply	other threads:[~2007-07-31  8:08 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-31  8:06 John Sigler [this message]
2007-07-31 10:27 ` BIOS implementors disabling the LAPIC Maciej W. Rozycki
2007-07-31 12:32   ` John Sigler
2007-07-31 12:55     ` Maciej W. Rozycki
  -- strict thread matches above, loose matches on Subject: below --
2007-07-31 12:53 Gregory Haskins

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