Getting CPU utilization information

How could I get the CPU utilization with time info of a process in linux? Basically I want to let my application run overnight. At the same time, I would like to monitor the CPU utilization during the period the application开发者_运维技巧 is run.

I tried top | grep appName >& log, it does not seem to return me anything in the log. Could someone help me with this?

Thanks.

vmstat and iostat can both give you periodic information of this nature; I would suggest either setting up the number of times manually, or putting a single poll into a cron job, and then redirecting the output to a file:

vmstat 20 4230 >> cpu_log_file

This would give you a snapshot of usage every 20 seconds for 24 hours.

install sysstat package and run sar

nohup sar -o output.file 12 8 >/dev/null 2>&1 &

use the top or watch command

PID    COMMAND      %CPU TIME     #TH  #WQ  #PORT #MREG RPRVT  RSHRD  RSIZE  VPRVT  VSIZE  PGRP  PPID  STATE    UID  FAULTS    COW    MSGSENT    MSGRECV    SYSBSD    SYSMACH   CSW       PAGEINS USER
10764  top          8.4  00:01.04 1/1  0    24    33    2000K  244K   2576K  17M    2378M      10764 10719 running  0    9908+     54     564790+    282365+    3381+     283412+   838+          27      root
10763  taskgated    0.0  00:00.00 2    0    25    27    432K   244K   1004K  27M    2387M  10763 1     sleeping 0    376       60     140        60         160       109       11        0       root

Write a program that invokes your process and then calls getrusage(2) and reports statistics for its children.

You can monitor the time used by your program with top while it is running.

Alternatively, you can launch your application with the time command, which will print the total amount of CPU time used by your program at the end of its execution. Just type time ./my_app instead of just ./my_app

For more info, man 1 time