In article <20050306022312.GD14713@snark.ptc.spbu.ru>
uwe@ptc.spbu.ru wrote:

>     df -hil -t nokernfs,procfs,null,fdesc
 :
> Any suggestions on how to debug it?  Do you see this on other sh3
> ports?

The command doesn't cause any problem on my dc:
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mirage-% ssh dignity
Enter passphrase for key '/home/tsutsui/.ssh/id_rsa': 
Last login: Sun Mar  6 20:26:35 2005
NetBSD 2.99.16 (DIGNITY) #397: Sun Mar 6 20:16:57 JST 2005

Welcome to NetBSD!

Sun Mar  6 20:32:54 JST 2005
dignity-% df -hil -t nokernfs,procfs,null,fdesc
Filesystem    Size      Used     Avail Capacity  iused    ifree  %iused  Mounted on
/dev/wd0a      95M      22M       69M    24%     1680    23662     6%   /
/dev/wd0f      95M      12M       78M    13%     1287    23479     5%   /var
/dev/wd0g     5.6G     1.4G      3.9G    26%   101403  1362915     6%   /usr
mfs:211        15M     512B       14M     0%        1     7677     0%   /tmp
dignity-% df -hil -t nokernfs,procfs,null,fdesc
Filesystem    Size      Used     Avail Capacity  iused    ifree  %iused  Mounted on
/dev/wd0a      95M      22M       69M    24%     1680    23662     6%   /
/dev/wd0f      95M      12M       78M    13%     1287    23479     5%   /var
/dev/wd0g     5.6G     1.4G      3.9G    26%   101403  1362915     6%   /usr
mfs:211        15M     512B       14M     0%        1     7677     0%   /tmp
dignity-%
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It also works enough to build under xsrc.
Does your kernel have a recent MMU fix?
http://mail-index.netbsd.org/source-changes/2004/12/30/0019.html

Or, if your machine has SH3 (not SH4), it might be SH3 specific problem.
You could also try options KSTACK_DEBUG, but I have never tried it.
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Izumi Tsutsui