Re: [vox-tech] postscript printer problem

[Henry House <hMAPSajhouse@houseag.com>]

On Mon, May 06, 2002 at 02:37:36PM -0700, Peter Jay Salzman wrote:
> begin Henry House <hajhouse@houseag.com> 
> > On Mon, May 06, 2002 at 01:16:35PM -0700, Mark K. Kim wrote:
> > > On Mon, 6 May 2002, Henry House wrote:
> > 
> > The Linux box that uses the printer has been up for months. But the lp
> > drivers are modules; perhaps that has something do do with it? I tried to
> > rmmod lp and rmmod segfaulted. It refuses to unload parport_pc (device or
> > resource busy). Here is the output of lsmod:
> > 
> > 	Module                  Size  Used by    Not tainted
> > 	nls_iso8859-1           2880   0  (autoclean)
> > 	isofs                  17376   0  (autoclean)
> > 	loop                    8624   0  (autoclean)
> > 	ide-probe-mod           7728   0  (autoclean)
> > 	ide-mod                63528   0  (autoclean) [ide-probe-mod]
> > 	soundcore               3908   0  (autoclean)
> > 	appletalk              22828   0  (autoclean)
> > 	nls_cp437               4384   0  (autoclean)
> > 	vfat                    9372   0  (autoclean)
> > 	fat                    30008   0  (autoclean) [vfat]
> > 	floppy                 45952   0  (autoclean)
> > 	nfsd                   65600  32  (autoclean)
> > 	lockd                  47168   1  (autoclean) [nfsd]
> > 	sunrpc                 63764   1  (autoclean) [nfsd lockd]
> > 	parport_pc             25320   1  (autoclean)
> > 	lp                         0   0  (deleted)
> > 	parport                25888   1  (autoclean) [parport_pc lp]
> > 	af_packet               9288   1  (autoclean)
> > 	serial                 45504   1  (autoclean)
> > 	unix                   15620 122  (autoclean)
> > 
> > Disturbing.
>  
> not really.  if another user space program accesses the printer device
> file, the module will fail to unload.   try "fuser /dev/lp0".
> 
> however, the SEGFAULT is troubling.  you may want to up the kernel.

I forgot to mention that I checked for processes using /dev/lp0 with lsof

	May  6 14:24:22 wotan kernel: esi: 00000001   edi: f88a6000   ebp: bfffe9ac   esp: c60fff64
	May  6 14:24:22 wotan kernel: ds: 0018   es: 0018   ss: 0018
	May  6 14:24:22 wotan kernel: Process rmmod (pid: 29043, stackpage=c60ff000)
	May  6 14:24:22 wotan kernel: Stack: f7935280 f88a7784 f88a6e95 f88a7700 f889e2c6 f7935280 f88a6000 fffffff0 
	May  6 14:24:22 wotan kernel:        f88a70f8 f88a7784 f88a6000 fffffff0 c011a837 f88a6000 fffffff0 dcffd000 
	May  6 14:24:22 wotan kernel:        bfffe9ac c0119b0a f88a6000 00000000 c60fe000 00000001 bfffe9ac c0106cdb 
	May  6 14:24:22 wotan kernel: Call Trace: [<f88a7784>] [<f88a6e95>] [<f88a7700>] [<f889e2c6>] [<f88a70f8>] 
	May  6 14:24:22 wotan kernel:    [<f88a7784>] [free_module+23/172] [sys_delete_module+294/568] [system_call+51/56] 
	May  6 14:24:22 wotan kernel: 
	May  6 14:24:22 wotan kernel: Code: 8b 42 28 85 c0 74 0c 39 d8 75 f3 8b 40 28 89 42 28 31 f6 83 

Does anyone follow the kernel mailing lists? I have found the search tools
next to useless, since they return matches from 1996 when I search for lp
driver problems. I'm very reluctant to re-boot the machine unless I know that
there is a fix for the problem in a newer kernel since this machine is used
interactively by people who don't like it when their processes dissappear ;-).

-- 
Henry House
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