task_struct contains mm_struct. If we have pid of the process then task_struct can be obtained from pid using following two methods. 1. Please check find_task_by_pid() function in kernel. We can write a similar macro to convert pid to task_struct. 2. We can write a macro that traverses all task starting from init_task and check the required pid. #define for_each_task(p) \ for (p = &init_task ; (p = p->next_task) != &init_task ; ) If process is the current one then current_thread_info()->task provides task_struct for current task. We can write a macro similar to current_thread_info(). pid-> task_struct->mm_struct. Regards Manoj Nayak