Re: Reading a file in the driver

[Erik Mouw]

On Fri, Dec 27, 2002 at 10:13:32AM -0500, David Anderson wrote:
> I am reading some data from a file byte by byte in my driver. Although it's not a good thing to read a file in the driver I have to do it. My file is quite big can contain about 1000 lines each line containing anywhere from 0 to 500 characters. I believe carry out 500000 reads is not a good thing. 
> 
> Any suggestions on how I can improve ??

Sure, do it from userland. Make a device node to which userland can write
the file you want. This nicely removes the policy problem of *which* file
to read from *what* location and puts it were it belongs: userland. With
this setup you can even read files from such exotic locations like other
servers or SQL databases.

If the driver needs to initiate the file reading, just startup a userland
helper that does the reads for you. See for example how the hotplug
subsystem calls /sbin/hotplug.

Erik

-- 
J.A.K. (Erik) Mouw
[e-mail]  [e-mail]
http://www-ict.its.tudelft.nl/~erik/