Arguments
The arguments to profile probes are as follows:
arg0
| The program counter (PC) in the kernel at the time that the probe fired,
or 0 if the current process was not executing in the kernel at the time that
the probe fired
|
arg1
| The PC in the user-level process at the time that the probe fired, or
0 if the current process was executing at the kernel at the time that the
probe fired
|
|
As the descriptions imply, if arg0 is non-zero then arg1 is zero; if arg0 is zero then arg1 is
non-zero. Thus, you can use arg0 and arg1 to
differentiate user-level from kernel level, as in this simple example:
profile-1ms
{
@ticks[arg0 ? "kernel" : "user"] = count();
}