Subject: Re: port-arm32/7122: Breakpoints lost under heavy swapping
To: Jason Thorpe <>
From: Bill Sommerfeld <>
List: tech-kern
Date: 03/10/1999 14:31:44
Hmm.  Thinking about problems with anon pages on arm..

I have a Shark with local swap disk and with /tmp in an MFS, and I
found that "make build" was rather flaky, blowing up maybe every 10
minutes or so with spurious syntax errors, until I switched to using
cc -pipe for everything.  I assume that the contents of the
intermediate preprocessor output files in /tmp were getting corrupted.

I should have reported this a while back. 

I found it very easy to reproduce.. put /tmp in MFS, try to build a
kernel from scratch on a 32meg shark while trying to get other work

Looking at what's in common between the lost breakpoints, and the mfs
problems, and assuming there's one bug underlying both problems.. MFS
stores the bits of the filesystem in the memory of the mount_mfs
process. I would guess that whatever bug is in there involves
something having to do with the kernel touching anonymous memory
regions out in userland..

				- Bill