While the first three lines are mandatory and always printed, the rest is
optional and may be omitted if no marks created yet.
+ Timerfd files
+ ~~~~~~~~~~~~~
+
+ pos: 0
+ flags: 02
+ mnt_id: 9
+ clockid: 0
+ ticks: 0
+ settime flags: 01
+ it_value: (0, 49406829)
+ it_interval: (1, 0)
+
+ where 'clockid' is the clock type and 'ticks' is the number of the timer expirations
+ that have occurred [see timerfd_create(2) for details]. 'settime flags' are
+ flags in octal form been used to setup the timer [see timerfd_settime(2) for
+ details]. 'it_value' is remaining time until the timer exiration.
+ 'it_interval' is the interval for the timer. Note the timer might be set up
+ with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value'
+ still exhibits timer's remaining time.
------------------------------------------------------------------------------
Configuring procfs