Subject: Re: AS1200 problems
To: David Hopper <dhop@nwlink.com>
From: Jason R Thorpe <thorpej@wasabisystems.com>
List: port-alpha
Date: 01/31/2002 22:54:30
On Thu, Jan 31, 2002 at 03:42:14PM -0800, David Hopper wrote:

 > I have been having frequent memory management faults on my AlphaServer 1200
 > 5/533.  I've been tracking NetBSD-current on this particular tincup since
 > December '99.  I _think_ I can trace the faults back to around the time of
 > the multiprocessor changes.
 > 
 > The memory management faults occur with seemingly random processes, but
 > most often when I increase the load on the machine:  it's happened most
 > frequently with imapd (2001a from pkgsrc), moving a large directory from a
 > RAID device to another SCSI HD, and more recently, and reproducibly, on a
 > build.sh on various processes soon after the libs have been installed into
 > destdir.  The machine can go for a month if I leave it to its
 > imap/webserving duties, or it faults daily if I am trying to sup & rebuild.
 > 
 > I thought it was the RAM, so I tried a build using brand-new Crucial memory
 > today.  Same mm fault:
 > 
 > CPU0	trap entry = 0x2 (memory management fault)
 > CPU0	a0	   = 0x0
 > CPU0	a1	   = 0x1
 > CPU0	a2	   = 0xffffffffffffffff
 > CPU0	pc	   = 0x0
 > CPU0	ra	   = 0x0
 > CPU0	pv	   = 0xfffffc000037d260
 > CPU0	curproc	   = 0xfffffc00rf98da00
 > CPU0	       pid = 8452, comm = cpp0
 > 
 > Then a hang on the sync to disk.
 > 
 > I'm at wit's end, but I absolutely will not install any other BSD.  I know
 > Jason uses an AS1200 for the multiproc stuff, so I can't imagine that he's
 > got the same troubles...

Yah, strange ... I put my AS1200 through a lot of work.  It's a paragon
of stability, in fact (I do a lot of gcc-current and binutils-current
testing on it).

It's really weird that both $pc and $ra are 0.  It's almost like you
have a trashed stack (restored bogus value into $ra, and then executed
a ret, putting that bogus value into $pc).

Can you use gdb to tell me what $pv points to?

-- 
        -- Jason R. Thorpe <thorpej@wasabisystems.com>