Re: upcalls from kernel code to user space daemons

[Bernd Petrovitsch]

On Mon, 2004-06-14 at 23:57, Chris Friesen wrote:
> Oliver Neukum wrote:
> 
> >  > userspace daemon loops on ioctl()
> >  > kernel portion of ioctl call goes to sleep until something to do
> >  > when needed, fill in data and return to userspace
> >  > userspace does stuff, then passes data back down via ioctl()
> >  > ioctl() puts userspace back to sleep and continues on with other work
> > 
> > You could just as well implement an ordinary read()
> 
> Not quite.  The userspace is passing data down as well.  I don't know how you'd 
> do that with read().

For this you use write().

	Bernd
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