Top not showing cpu usage even remotely accurately

[Dan Nelson]

In the last episode (Sep 14), Tamouh H. said:
> This is one TOP that freaked me out, notice Idle CPU is 70% while the
> process is showing it is using 99% of CPU. systat draws more accurate
> picture, however, load average is still useless as far as performance
> monitoring :
> 
> last pid: 10174;  load averages:  1.63,  1.44,  1.20                                                  up 4+00:25:19  00:39:20
> 169 processes: 2 running, 166 sleeping, 1 zombie
> CPU states: 25.8% user,  0.0% nice,  0.7% system,  0.1% interrupt, 73.4% idle
> Mem: 1316M Active, 1445M Inact, 297M Wired, 127M Cache, 112M Buf, 79M Free
> Swap: 8762M Total, 2096K Used, 8760M Free
> 
>   PID USERNAME PRI NICE   SIZE    RES STATE  C   TIME   WCPU    CPU COMMAND
> 13362 root     111    0 36444K 34196K CPU3   3  50:06 98.88% 98.88% perl5.8.7
> 90391 root      96    0 27356K 26236K select 2   0:06  0.54%  0.54% perl5.8.7
> 79619 nobody     4    0   209M 84640K sbwait 1   0:09  0.39%  0.39% httpd
> 10161 root      97    0  6712K  4752K select 2   0:00  1.40%  0.20% exim-4.62-0
> 79649 nobody    20    0   210M 84464K lockf  0   0:06  0.15%  0.15% httpd

You have a 4-cpu box and pid 13362 is using 99% of one CPU.  The other
3 are idle, so your %idle is going to be around 75%.  Looks pretty
accurate to me :)

-- 
	Dan Nelson
	dnelson at allantgroup.com