measuring time spend of a process

measuring time spend of a process

[Frits Hoogland]

I want to measure the real cpu time, time in runqueue, and time in
interruptible and uninterruptible state of a process.

below is my current systemtap script. is this the best way to do that?
(please mind I am using version 0.7.2 which comes with Centos 5.3)

any comments are welcome and appreciated!

frits

--begin--
// Return the task of the given process id
function pid2task:long (pid:long) %{ /* pure */
    struct task_struct *t = NULL;
    pid_t t_pid  = (pid_t)(long)THIS->pid;
    rcu_read_lock();
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
      t = find_task_by_vpid (t_pid);
#else
      t = find_task_by_pid (t_pid);
#endif
    rcu_read_unlock();
    THIS->__retvalue = (long)t;
    CATCH_DEREF_FAULT();
%}

global task
global prev_time_us
global running, interruptible, uninterruptible
global start_cpu_time, on_cpu_time
global slices, start_time

probe begin{
        task=pid2task(target())
        printf("Start of profile of pid: %d, task: %d\n", target(), task )
        start_time=gettimeofday_us()
        prev_time_us=gettimeofday_us()
}
probe timer.profile {
        if( task_state( task ) == 0 ) {
                running += gettimeofday_us() - prev_time_us
        } else if( task_state( task ) == 1 ) {
                interruptible += gettimeofday_us() - prev_time_us
        } else if( task_state( task ) == 2 ) {
                uninterruptible += gettimeofday_us() - prev_time_us
        }
        prev_time_us=gettimeofday_us()
}
probe scheduler.cpu_on {
        if( pid() == target() ) {
                start_cpu_time=gettimeofday_us()
                slices++
        }
}
probe scheduler.cpu_off {
        if( pid() == target() ) {
                if( start_cpu_time != 0 ) {
                        on_cpu_time += gettimeofday_us()-start_cpu_time
                }
        }
}


probe end{
        printf("Pid: %d, running total %d, running cpu %d, running
queue %d, inter %d, uninter %d, total time %d (%d), slices %d,
ave/slice %d\n", target(), running, on_cpu_time, running-on_cpu_time,
interruptible, uninterruptible, gettimeofday_us()-start_time,
running+interruptible+uninterruptible, slices, on_cpu_time/slices)
}
--end--