April 4, 2011
9:45 a.m.
A daemon sleeps in the background. User can enter a string through the proc interface. Whenever a string is entered, the daemon is woke. The daemon keeps a copy of the last entered string in a variable. Initially the variable is initialized to NULL. When the daemon wakes, it checks if the string entered is same as the previous one or a new string is entered. When the string is entered, in case the new or the old strings are NULL, or in case the entered string is same as the old string the daemon goes back to sleep (with the help of the function interruptible_sleep_on().
Don't use interruptible_sleep_on use wait_event* instead. thanks, Daniel. [1] http://lxr.linux.no/linux+v2.6.38/include/linux/wait.h#L570