In case of kernel thread is running on behalf of user process. In meantime a timer interrupt arrives(slow interrupt). Now after end of timer interrupt are Bottom halves, task queues invoked ? (offcourse Scheduler is not invoked as kernel is not pre emptive) Please clarify . Thanks, Nirranjan.K - 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/