Re: State of devfs in 2.6?

Holger Schurig
2003-12-09T10:08:46Z

>> * space. devfs doesn't eat space like the MAKEDEV approach.
>
> Um, devfs does actually use a non-zero amount of code...

Yeh, it uses code. But if you look into a MAKEDEV bases file system, you see
hundreds of device files. Which uses inode and directory space on the
medium, may it be e2fs or jffs2.

I did not measure if the code for devfs is smaller as the code+config files
for udev. But I didn't make a statement about this.

> For a typical embedded device with about 5 entries in /dev I wouldn't
> be surprised if devfs used a lot _more_ space...

# find /dev | wc -l
326

"Embedded" is not automatically a washing maschine with only 5 entries, it
can be a full blown Linux computer with 400 MHz, Framebuffer, USB Host, USB
Client, 7 serial ports for GSM, Barcode Scanner, Whatever, and so on. Like
our device.

However, even on such hardware-rich devices you usually have a constraint on
Flash Memory size. So having things small & simple is nice. That makes room
for the user applications & data.

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