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    SubjectRe: PROPOSAL: /proc/dev
    Andrea Arcangeli writes:
    > On Sun, 4 Jan 1998, James Mastros wrote:
    >
    > >On Sun, 4 Jan 1998, Andrea Arcangeli wrote:
    > >> On Sat, 3 Jan 1998, Richard Gooch wrote:
    > >>
    > >> >The reason my scheme doesn't depend on kerneld is that if a driver is
    > >> >built-in/loaded by a boot script, the /dev entries for that driver are
    > >> >registered in the startup code. So, on a system like mine where all
    > >> >drivers are either built-in or automatically installed by a boot
    > >> >script, /dev would be fully populated. An attempt to open(2) an entry
    > >> >in /dev which did not exist would cause devfs to return -ENODEV
    > >> >because kerneld isn't running.
    >
    > ...and if kerneld is running kerneld will "mknod" the device in /devfs.

    No, kerneld will load the module and the driver will call
    dev_register() which will create the entry.

    > >> - You could implement that more easily without use kerneld.
    > >Yes, but then we don't have module autoloading.
    >
    > I am not talking about modules. The open(2) implementation that Richard
    > proposed in the paragraph above is whole related to static device and not
    > only module.
    >
    > >> - I think this is totally wrong for programs or people that check in /dev
    > >> for a device before try to open it, or at least is a mess.
    > >WHAT!!! The whole point of a virtual devfs is that you can do a "ls /dev"
    > >to see what devices are currently accessable. And most actions on a divice
    > >start with a call to open() (or mount()).
    >
    > Richard in the paragraph I quoted, proposed a devfs implementation that
    > don' t show what devices are currently accessible, but only the ones
    > opened(2).

    No, *all* devices available through built-in drivers and loaded
    modules are shown. And devices registered through modules previously
    loaded but now unloaded are also shown.

    > >> - If you want to make something useful, your devfs must be populated from
    > >> _all_ kernel devices at boot with 600 permission and it must not remove
    >
    > Obviously I want to mean _all_ and __only__ kernel devices linked or
    > insmodded with the kernel.

    Er, yes, that's what I suggested...

    > I know but I am a bit conservative when all just works perfect and
    > efficient...

    Well, I don't agree that the existing scheme is efficient. It "works"
    but it's clumsy.

    Regards,

    Richard....

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