Subject: Re: kern/32145: 3 CPUs found with single CPU HT machine in current
To: None <,,>
From: Quentin Garnier <>
List: netbsd-bugs
Date: 11/23/2005 01:25:01
The following reply was made to PR kern/32145; it has been noted by GNATS.

From: Quentin Garnier <>
Subject: Re: kern/32145: 3 CPUs found with single CPU HT machine in current
Date: Wed, 23 Nov 2005 02:16:17 +0100

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 On Wed, Nov 23, 2005 at 01:09:00AM +0000, wrote:
 > >Number:         32145
 > >Category:       kern
 > >Synopsis:       3 CPUs found in single HT CPU machine in current
 > >Confidential:   no
 > >Severity:       serious
 > >Priority:       medium
 > >Responsible:    kern-bug-people
 > >State:          open
 > >Class:          sw-bug
 > >Submitter-Id:   net
 > >Arrival-Date:   Wed Nov 23 01:09:00 +0000 2005
 > >Originator:     Tracy Di Marco White
 > >Release:        NetBSD 3.99.11
 > >Organization:
 > TNF
 > >Environment:
 > System: NetBSD 3.99.11 NetBSD 3.99.11 (GENERIC.MPACP=
 I) #1: Tue Nov 22 15:28:18 CST 2005
 > Architecture: i386
 > Machine: i386
 > >Description:
 > # dmesg|grep cpu
 > cpu0 at mainbus0: apid 0 (boot processor)
 > cpu1 at mainbus0: apid 1 (application processor)
 > cpu2 at mainbus0: (uniprocessor)
 > # dmesg | grep acpi|grep OemId
 > acpi0: X/RSDT: OemId <PTLTD ,  RSDT  ,06040000>, AslId < LTP,00000000>
 > >How-To-Repeat:
 > install! Boot an MPACPI kernel.
 What happens is that the ACPI table is known as buggy, thus not used for
 bus scanning.  The way we currently do things, mpacpi_scan_apics() will
 return 0, although it already has attached the CPUs.  As a result, a
 third CPU gets attached as a uniprocessor, as if MPACPI and MPBIOS had
 To fix this, mpacpi_scan_apics() should indicate whether it has probed
 the CPUs or not, as it really has to return an error when the ACPI table
 is quirk'd out to indicate buses should not be probed using values found
 walking the MADT.
 Quentin Garnier - -
 "When I find the controls, I'll go where I like, I'll know where I want
 to be, but maybe for now I'll stay right here on a silent sea."
 KT Tunstall, Silent Sea, Eye to the Telescope, 2004.
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