Re: [PATCH] Show version information for built-in modules in sysfs

[Dmitry Torokhov <dtor@vmware.com>]

On Wed, Dec 15, 2010 at 03:53:12PM -0800, Dmitry Torokhov wrote:
> On Wed, Dec 15, 2010 at 03:25:27PM -0800, Alexey Dobriyan wrote:
> > On Thu, Dec 16, 2010 at 12:14 AM, Dmitry Torokhov <dtor@vmware.com> wrote:
> > > On Wed, Dec 15, 2010 at 02:06:03PM -0800, Alexey Dobriyan wrote:
> > >> On Thu, Dec 16, 2010 at 12:00 AM, Dmitry Torokhov <dtor@vmware.com> wrote:
> > >> > Currently only drivers that are built as modules have their versions
> > >> > shown in /sys/module/<module_name>/version, but this information might
> > >>
> > >> Can you create just /sys/module/x?
> > >> Module version info is quite useless by itself.
> > >
> > > It is as useful as in the case where driver is built as a module. I am
> > > just trying to unify the behavior a bit.
> > >
> > > Code-wise it is almost as cheap to add /sys/module/x/version as adding
> > > just the directory.
> > 
> > OK.
> > 
> > Still, people are using /sys/module/x presence as indicator of modular
> > built (unsurprisingly).
> > 
> > http://codesearch.google.com/codesearch/p?hl=en#wZuuyuB8jKQ/src/third_party/autotest/files/client/profilers/powertop/src/bluetooth.c&q=/sys/modules&sa=N&cd=3&ct=rc&l=105
> 
> Yeah, I hate to disappoint them but it will break as soon as someone
> adds a module_param() to one of the objects... That's even without my
> changes.

Looking at this some more they are concerned whether bluetooth is
present in the kernel, not whether it is loaded: if you care about power
consumption you need to shut off BT interface whether BT core is a
module or built-in. In this regard I'd say my change will make that code
behave better ;)

-- 
Dmitry