On Thu, Jan 01, 2004 at 02:18:55AM +0100, Helge Hafting wrote:
> On Tue, Dec 30, 2003 at 04:29:42PM -0800, Greg KH wrote:
> >
> > 2) We are (well, were) running out of major and minor numbers for
> > devices.
>
> devfs tried to fix this one by _getting rid_ of those numbers.
> Seriously - what are they needed for?
But devfs failed in this. The devfs kernel interface still requires a
major/minor number to create device nodes.
Hopefully I can work on fixing this up in 2.7.
thanks,
greg k-h
On Fri, Jan 02, 2004 at 09:59:38PM -0800, Greg KH wrote:
> On Thu, Jan 01, 2004 at 02:18:55AM +0100, Helge Hafting wrote:
> > On Tue, Dec 30, 2003 at 04:29:42PM -0800, Greg KH wrote:
> > >
> > > 2) We are (well, were) running out of major and minor numbers for
> > > devices.
> >
> > devfs tried to fix this one by _getting rid_ of those numbers.
> > Seriously - what are they needed for?
>
> But devfs failed in this. The devfs kernel interface still requires a
> major/minor number to create device nodes.
>
Yes. The numbers went unused in the common case of opening a device by name though.
> Hopefully I can work on fixing this up in 2.7.
Interesting - how do you plan to do this?
There must be some connection from device node to driver. Devfs had
a pointer in the inode. The old way has numbers, and spend time on
a search.
Are you considering a sort of "minimal devfs" managed by udev?
Helge Hafting
On Sat, Jan 03, 2004 at 04:22:41PM +0100, Helge Hafting wrote:
> On Fri, Jan 02, 2004 at 09:59:38PM -0800, Greg KH wrote:
> > On Thu, Jan 01, 2004 at 02:18:55AM +0100, Helge Hafting wrote:
> > > On Tue, Dec 30, 2003 at 04:29:42PM -0800, Greg KH wrote:
> > > >
> > > > 2) We are (well, were) running out of major and minor numbers for
> > > > devices.
> > >
> > > devfs tried to fix this one by _getting rid_ of those numbers.
> > > Seriously - what are they needed for?
> >
> > But devfs failed in this. The devfs kernel interface still requires a
> > major/minor number to create device nodes.
> >
> Yes. The numbers went unused in the common case of opening a device by name though.
No, they were not. RTFS, please.
On Sat, Jan 03, 2004 at 04:22:41PM +0100, Helge Hafting wrote:
> > Hopefully I can work on fixing this up in 2.7.
>
> Interesting - how do you plan to do this?
Probably something like the current interface for USB minor numbers when
CONFIG_USB_DYNAMIC_MINORS is enabled. The drivers will request a
certian major/minor, but the kernel will just give it whatever it feels
like.
That's my first guess, actual implementation will probably differ wildly
:)
thanks,
greg k-h