Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 24 Apr 1996 11:21:37 +0930 (CST)
From:      Michael Smith <msmith@atrad.adelaide.edu.au>
To:        scrappy@ki.net (Marc G. Fournier)
Cc:        hasty@rah.star-gate.com, current@FreeBSD.org, hackers@FreeBSD.org
Subject:   Re: Intelligent Debugging Tools...
Message-ID:  <199604240151.LAA13635@genesis.atrad.adelaide.edu.au>
In-Reply-To: <Pine.NEB.3.93.960423174633.1690B-100000@freebsd.ki.net> from "Marc G. Fournier" at Apr 23, 96 06:00:06 pm

next in thread | previous in thread | raw e-mail | index | archive | help
Marc G. Fournier stands accused of saying:
> FreeBSD 2.1-STABLE #0: Tue Apr 23 10:33:56 EDT 1996
>     scrappy@ki.net:/usr/src/sys/compile/kinet
> CPU: i486 DX4 (486-class CPU)
>   Origin = "GenuineIntel"  Id = 0x480  Stepping=0
>   Features=0x3<FPU,VME>
> real memory  = 16777216 (16384K bytes)
> avail memory = 14835712 (14488K bytes)
> Probing for devices on PCI bus 0:
> chip0 <SiS 85c496> rev 49 on pci0:5

Ok.  This guy is known to work pretty well, as long as you avoid ISA
busmasters.

> sctarg0(noadapter::): Processor Target 

Wozzis?  You have a scanner or something?

> 	Oh, the motherboard is an ACER AP43 with a 486DX4-100
> CPU, and sio[01] are both onboard serial.

Jumpered for write-back or write-through?  Which cache Tagram are you
using?  Is the board jumpered correctly for it?

> 	The memory is one 16Meg SIMM, and pstat shows:

Speed?  Manufacturer?

> 	My two most recent panics had to do with vm_page_alloc(), which 
> I *think* have to do with swap -or- RAM, and pmap_zero_page(), both of
> which I've been told no one else is experiencing (and I've gone through 
> the GNaTs database for anything similar to no avail), which I believe.

The problem, such as it is, is that these pieces of code depend intimately
on some _very_ heavily accessed parts of memory, and if there's anything
wrong with these parts of memory, they cause a panic.

> 	And I have no problems believing that it *may* be a hardware 
> problem, but what would be nice is some non-"trial and error" method of
> narrowing down the problem.  Some way of having the panic that vm_page_alloc()
> produces send out an error message that states *where* the panic occurred...
> ie. in RAM or in swap space, or as a result of either.  

Check the source of the panic in the code, and there you have it.

> Marc G. Fournier                                  scrappy@ki.net

-- 
]] Mike Smith, Software Engineer        msmith@atrad.adelaide.edu.au    [[
]] Genesis Software                     genesis@atrad.adelaide.edu.au   [[
]] High-speed data acquisition and      (GSM mobile) 0411-222-496       [[
]] realtime instrument control          (ph/fax)  +61-8-267-3039        [[
]] Collector of old Unix hardware.      "Where are your PEZ?" The Tick  [[



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199604240151.LAA13635>