|
|
In ac_flag, the AFORK flag is turned on by each
fork(S)
and turned off by an
exec(S).
The ac_comm member is inherited from the parent process and
is reset by any call to
exec(S).
Each time the system charges the process with a clock tick,
it also adds the current process size
to the ac_mem member, computed as follows:
(data size) + (text size) / (number of in-core processes using text)
The value of ac_mem/ac_stime
can be viewed as an approximation to the
mean process size, as modified by text-sharing.
ac_mem
value for a short-lived command gives little information about
the actual size of the command, because ac_mem
may be incremented while a different command
(for example, the shell) is being executed by the process.
X/Open Portability Guide, Issue 3, 1989 .