AIX 5L Problem Determination - IBM Redbooks

second. Large values indicate a CPU-intensive process and result in a lower
process priority, while small values indicate an I/O-intensive process and result
in a more favorable priority. In the following example, tctestprog is running, which
is a CPU-intensive program. The vmstat command output shows that about 25
percent of the CPU is used by usr processes.
# vmstat 2 3
kthr memory page faults cpu
----- ----------- ------------------------ ------------ ----------r
b avm fre re pi po fr sr cy in sy cs us sy id wa
0 0 26468 51691 0 0 0 0 0 0 100 91 6 47 0 53 0
1 1 26468 51691 0 0 0 0 0 0 415 35918 237 26 2 71 0
1 1 26468 51691 0 0 0 0 0 0 405 70 26 25 0 75 0
The ps command is useful in this situation. The following formatting sorts the
output so that the third column has the biggest value at the top, and shows only
five lines from the total output.
# ps -ef | sort +3 -r |head -n 5
UID PID PPID C STIME TTY TIME CMD
root 22656 27028 101 15:18:31 pts/11 7:43 ./tctestprog
root 14718 24618 5 15:26:15 pts/17 0:00 ps -ef
root 4170 1 3 Jun 15 - 12:00 /usr/sbin/syncd 60
root 21442 24618 2 15:26:15 pts/17 0:00 sort +3 -r
From the previous example, you can tell that tctestprog is the process with the
most-used CPU in recent history.
The TIME column
The second value mentioned is the TIME value. This value is generated with all
flags, and it shows the total execution time for the process. This calculation does
not take into account when the process was started, as seen in the following
output. The same test program is used again, and event, though the C column
shows that the process gets a lot of CPU time, is not yet on top in the TIME
column:
# ps -ef | sort +3 -r |head -n 5
UID PID PPID C STIME TTY TIME CMD
root 18802 27028 120 15:40:28 pts/11 1:10 ./tctestprog
root 9298 24618 3 15:41:38 pts/17 0:00 ps -ef
root 15782 24618 2 15:41:38 pts/17 0:00 head -n 5
root 24618 26172 2 Jun 21 pts/17 0:03 ksh
# ps -e |head -n 1 ; ps -e|egrep -v "TIME|0:"|sort +2b -3 -n -r|head -n 10
PID TTY TIME CMD
4170 - 12:01 syncd
4460 - 2:07 X
3398 - 1:48 dtsession
18802 pts/11 1:14 tctestprog
242 IBM ^ Certification Study Guide - AIX 5L Problem Determination Tools and Techniques