> I have an userspace application running, which communicates to a kernel modules > using IOCTLs. Now, from time to time, the kernel needs to send a message back to the > application. Now one alternative would be that the app polls the kernel using IOCTLs > to see if any message is waiting. How can I avoid that and send a message directly > as in a callback or signal? When you use ioctl, you have to have a file descriptor. It should be possible to implement poll syscall to work with that descriptor (character device or proc file). -------------------------------------------------------------------------------- - Jan Hudec `Bulb' <bulb@ucw.cz> -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/