Subject: Re: Lockup with GENERIC-MP kernel (05-19-03)
To: Matt Rickard <mjr318@psu.edu>
From: Frank van der Linden <fvdl@netbsd.org>
List: tech-kern
Date: 05/21/2003 01:20:18
On Tue, May 20, 2003 at 06:20:01PM -0400, Matt Rickard wrote:
> 	checking if getcwd() calls popen() ...
> 
> On the console that I am doing the build on, I am able to type (or at
> least echo characters to the screen), but the input is ignored.  I can't
> ctrl-c to kill the task.  I can switch to other virtual consoles, but
> cannot input anything at all.

That spells 'locking problem', and indeed, a LOCKDEBUG kernel spews:

switching with held simple_lock 0xc03d1f30 CPU 1 ../../../../kern/vfs_cache.c:301
simple_lock_switchcheck(e4dc0400,0,0,c0228144,e4dc0400) at netbsd:simple_lock_sw
itchcheck+0x18
mi_switch(e4dc0400,0,1cd,c023245f,0) at netbsd:mi_switch+0x48
ltsleep(c03d1180,204,c03717e8,0,c0406d1c) at netbsd:ltsleep+0x2ef
reaper(e4dc0400,0,0,0,c010030c) at netbsd:reaper+0x6c

..however, this doesn't make sense, since the lock taken at that
line is not held ever by the reaper, or can it ever be held 
in any way when a process sleeps. So at first glance I can't
figure out what's going on there.

- Frank


-- 
Frank van der Linden                                            fvdl@netbsd.org
===============================================================================
NetBSD. Free, Unix-like OS. > 45 different platforms.    http://www.netbsd.org/