Re: LANANA: To Pending Device Number Registrants

Alexander Viro
2001-05-15T17:32:53Z

On Tue, 15 May 2001, James Simmons wrote:

> What I wish was done was the very first ioctl call was a generic ioctl
> call to pass driver specific data. Basically you have something like this:
>
> struct fb_driver_specific_data {
> __u32 magic_identifier;
> __u32 size_of_data_packet;
> char *data_buffer;
> }

It's called write(2). magic_identifier: which file we are writing to.
size_of_data_packet: length. data_buffer: buffer we write from.

And if write() has too much overhead - we'd better fix _that_, because
it's much more likely hotspot than ioctl ever will be.