Re: DEVFSv50 and /dev/fb? (or /dev/fb/? ???)

Andrea Arcangeli (arcangeli@mbox.queen.it)
Thu, 6 Aug 1998 01:35:01 +0200 (CEST)


On Wed, 5 Aug 1998, Shawn Leas wrote:

>1) No need for userland created devices, as the driver will register them
>for you.

But then you still (of course) have to care about owners and permissions
so an additional MAKEDEV is not a big overhead compared.

>2) Quicker access to the resource due to no waiting for a big /dev
>directory lookup.

andrea@dragon:/tmp/prova$ while :; do >$RANDOM; done

andrea@dragon:/tmp/prova$ ls | wc -l
4182
andrea@dragon:/tmp/prova$ ls | head -1
1
Broken pipe
andrea@dragon:/tmp/prova$ time ls -l 1
-rw-rw-r-- 1 andrea internal 0 Aug 6 01:29 1

real 0m0.087s
user 0m0.010s
sys 0m0.010s

>3) Less administrative overhead in maintaining /dev and a MAKEDEV script.

You need to save and restore properties and ownership of devfs every
boot/shutdown.

>4) No maj/min device node limits, such as the number of them you can have.

Yes, good workaround.

Andrea[s] Arcangeli

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