Hello... > My idea is to hook some system calls as open, read and write > operations and log the status (for instance the current time) of each > one to a file and after that post process the log file to figure out > the system response time. Is it feasible? I don't know about LSM, but KProbe might serve your need here. Create a probe on function's entry and exit....record the timestamps..and do the necessary calculation based on these data. regards Mulyadi -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/