Re: [linux-usb] Re: USB device allocation
H. Peter Anvin (hpa@transmeta.com)
9 Oct 1999 05:48:43 GMT
Followup to: <yd8oge9l2cd.fsf@hoshi.engr.sgi.com>
By author: Scott Henry <scotth@sgi.com>
In newsgroup: linux.dev.kernel
>
> >>>>> "T" == Theodore Y Ts'o <tytso@MIT.EDU> writes:
>
> T> However, even if you use this type of approach for /devfs, it's still a
> T> cumbersome interface. Consider that with a /proc/devices-style
> T> approach, a one or two read()'s will allow you to get all of the
> T> information you need.
>
> T> With a /devfs approach, you will still need to readdir() through all of
> T> /devfs, figure out what changed, and then stat the device to see what
> T> has differed.
>
> The current devfs patches have a special device file (/dev/.devfsd)
> for devfsd to listen to for changes. It doesn't have to scan the
> /dev directory for _that_ reason. At least that's what the docs say--
> I haven't looked at the code.
>
I think a device daemon makes a lot of sense, as does a standard
kernel notification mechanism for it. I do make the observation that
if you have a device node management daemon, there is no need for the
virtual device filesystem. devfsd (devd) *does* make a lot of sense;
it is the rest of the filesystem that doesn't. What I would like to
see is devd, but operating on a physical filesystem where data can be
retained.
-hpa
--
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/