negative mod use count

negative mod use count

[Boris Dragovic]

hi,
what does negative module use count mean?

lynx

Re: negative mod use count

[Brian Gerst]

Boris Dragovic wrote:
> 
> hi,
> what does negative module use count mean?

A bugged module.

--

				Brian Gerst

Re: negative mod use count

[Frank v Waveren]

On Wed, Feb 28, 2001 at 03:08:11PM -0500, Brian Gerst wrote:
> > what does negative module use count mean?
> A bugged module.

Not at all. A non-zero usage count means the module can't be unloaded.
Whatever the module does with the usage count apart from that is
completely it's own choice.

-- 
Frank v Waveren                                      Fingerprint: 0EDB 8787
fvw@[var.cx|dse.nl|stack.nl|chello.nl] ICQ#10074100     09B9 6EF5 6425 B855
Public key: http://www.var.cx/pubkey/fvw@var.cx-gpg     7179 3036 E136 B85D

Re: negative mod use count

[Russell King]

On Wed, Feb 28, 2001 at 09:31:46PM +0100, Frank v Waveren wrote:
> On Wed, Feb 28, 2001 at 03:08:11PM -0500, Brian Gerst wrote:
> > > what does negative module use count mean?
> > A bugged module.
> 
> Not at all. A non-zero usage count means the module can't be unloaded.
> Whatever the module does with the usage count apart from that is
> completely it's own choice.

A negative module use count (specifically "-1") depends on whether a
module has a "can_unload" routine.  If it does not have a "can_unload"
routine, then chances are either the module decided "I can never be
removed" or else the module is buggy.

However, if a "can_unload" routine does exist (as in ipv6) then the
module use count is unconditionally set to "-1".

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: negative mod use count

[Keith Owens]

On Wed, 28 Feb 2001 20:58:06 +0100, 
Boris Dragovic <lynx@falcon.etf.bg.ac.yu> wrote:
>what does negative module use count mean?

Either an extra MOD_DEC_USE_COUNT was issued (buggy code) or the module
has a can_unload() function.  When modules define a can_unload()
routine then the use count is always displayed as -1 because the module
decides if it can be unloaded.

Re: negative mod use count

[Dr. Kelsey Hudson]

On Wed, 28 Feb 2001, Boris Dragovic wrote:
> what does negative module use count mean?

That means that there's a bug in someone's driver.
For some reason, the function to decrement the module use is called more
than once when a controlling process releases use of a module. 

This will prevent you from being able to 'rmmod' or 'modprobe -r' it; a
"Device or resource busy" error or similar will result IIRC. 

Submit a bug to the driver maintainer.

 Kelsey Hudson                                           khudson@ctica.com 
 Software Engineer
 Compendium Technologies, Inc                               (619) 725-0771
---------------------------------------------------------------------------     

Re: negative mod use count

[Russell King]

On Thu, Mar 01, 2001 at 04:55:30PM -0800, Dr. Kelsey Hudson wrote:
> On Wed, 28 Feb 2001, Boris Dragovic wrote:
> > what does negative module use count mean?
> 
> That means that there's a bug in someone's driver.

Not necessarily.  Please read the other replies (specifically mine) to
discover the real answer as to why modules can _legally_ have negative
use counts.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: negative mod use count

[Boris Dragovic]

> Not necessarily.  Please read the other replies (specifically mine) to
> discover the real answer as to why modules can _legally_ have negative
> use counts.

thanks to all the replies, I think it is a bug in the module since the
use count is -3 :). it is ltmodem driver for lucent win modems...

thnx,
lynx