Subject: multisegment memory problems
To: None <tech-kern@NetBSD.ORG>
From: Todd Vierling <tv@pobox.com>
List: tech-kern
Date: 07/13/1998 11:08:22
I have cc1 coredumps that randomly happen on files that make cc1 grow >16MB;
I have sendmail randomly thinking users are unknown when the system is at
high load; and I have pine processes coredumping when their indices and
buffers go beyond 16MB.

I'm convinced that there's something very wrong with MNN, or some other
aspect of the VM system, and I dare anyone with a Shark to reproduce an easy
testcase to prove that it's happening.  This isn't arm32-specific, but the
sharks I have (both of them!  Bad memory, bah.) are the easiest way I've
found to consistently reproduce the problem.  There's a recent PR for
port-amiga that references this. 

Testcase (remember, this is for sharks with the standard 32MB):  Download
and configure binutils 2.9.1 for a target of sparc-netbsd (or
sparc-anything).  Turn off process limits (unlimit under csh).  Once
configured, go into the opcodes directory and "make sparc-opc.o".  cc1
should go a little fritzy and show you segments of some other file on your
system that may currently be accessed or sitting in some random unused VM
page.  Running the same test multiple times should show you the same
weirdness. 

I can reproduce this on both Sharks, and the random behavior of Sendmail is
a little shocking to go with this.  Any ideas?

-- 
-- Todd Vierling (Personal tv@pobox.com; Bus. todd_vierling@xn.xerox.com)