#! /usr/bin/env stap

global fault_entry_time, fault_address, fault_access
global time_offset

probe begin { time_offset = gettimeofday_us() }

probe vm.pagefault {
  t = gettimeofday_us()
  p = pid()
  fault_entry_time[p] = t
  fault_address[p] = address
  fault_access[p] = write_access ? "w" : "r"
}

probe vm.pagefault.return {
  t=gettimeofday_us()
  p = pid()
  if (!(p in fault_entry_time)) next
  e = t - fault_entry_time[p]
  if (vm_fault_contains(fault_type,VM_FAULT_MINOR)) {
    ftype="minor"
  } else if (vm_fault_contains(fault_type,VM_FAULT_MAJOR)) {
    ftype="major"
  } else {
    next #only want to deal with minor and major page faults
  }

  printf("%d:%d:%p:%s:%s:%d\n",
	t - time_offset, p, fault_address[p], fault_access[p], ftype, e)
  #free up memory
  delete fault_entry_time[p]
  delete fault_address[p]
  delete fault_access[p]
}