[suspend/resume] Re: userspace notification from module

["Bartłomiej Zimoń" <uzi18@o2.pl>]

Dnia 2 stycznia 2010 15:04 	Daniel Borkmann <danborkmann@googlemail.com> napisał(a):
> Hi Bartłomiej,
> 
> Bartłomiej Zimoń wrote:
> > Dnia 2 stycznia 2010 13:36 	Daniel Borkmann <llug.dan@googlemail.com> napisał(a):
> > I will explain more what i'm going to do.
> > The idea is simple. Kernel before suspend/resume sends notification to 
> > registered kernel objects. So i have written small module to register
> > there and want now pass these data to /dev/file. It is 1byte so not a big deal.
> > 
> > I'm searching now for notification about new byte in buffer, as it is almost 
> > clear for async: http://www.xml.com/ldd/chapter/book/ch05.html#t4
> > but for sync still haven't find.
> 
> This sounds very interesting... a "hack" could be the following:
> 
> Register your pids to the kernel module, e.g. via ioctl, and if the
> (intra-kernel) notification will be delivered to your module you just
> send a signal to your registered processes via kill_proc_info(). Guess
> this is at least better than polling a file or sth similar.
> 
> I guess netlink could be the "cleaner" solution, but with more overhead?!
> 

This looks like more simple and could be good, after all i think about sending this 
module here to add to kernel. So if this solution could be ok i will start to code this part.

Question is now what signal to choose to not terminate process and to be compatible 
with rest of Linux kernel?

Best regards
Bartłomiej Zimoń