From owner-freebsd-smp  Wed Jun  9 15:24:41 1999
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Date: Wed, 9 Jun 1999 18:25:05 -0400
From: Richard Cownie <tich@ma.ikos.com>
Message-Id: <199906092225.SAA01166@par28.ma.ikos.com>
To: freebsd-current@freebsd.org, freebsd-smp@freebsd.org
Subject: 4-way SMP broken ?
Cc: tich@ma.ikos.com
Sender: owner-freebsd-smp@FreeBSD.ORG
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Hi,

I've been trying to install 19990604-CURRENT on a couple of SC450NX
boxes.  It works fine with 2 cpu's, but an SMP kernel with 4 cpu's
falls over very quickly (I think while it's setting up the APIC
stuff, or very shortly after - the messages about APIC bus ids appear
on the screen very briefly, then the machine reboots itself).

Does anyone know a) when was the last time it worked on 4 cpu's
b) what's changed recently which might relate to this.

Also in trying to figure this out I looked at the DRAM probing
code in /usr/src/sys/i386/i386/machdep.c:getmemsize(), and it looks
as though it's not safe for >2GB (e.g. comparisons of byte addresses
against signed "int end").  It would also be good if this probing
code was carefule not to ventrue past 4GB-64MB (PCI device space) -
then a generic kernel could work on a 4GB machine without any tweaking,
which would simplify installation - I get nervous shuffling DIMMs
in and out of the machine ...

Thanks
   Richard Cownie (tich@ma.ikos.com)


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