Does 'top' work on multi-processor systems?

[John Almberg]

I have a 3 month old server with two quad-core processors, 8G of RAM,  
and an array of fast hard drives. The two main applications are web  
server and mail server. There are only about 20 small-business  
websites and approx. 40 email accounts on the server. i.e., not much.

In terms of actual usage, performance is great. Web pages load fast,  
and email is processed quickly. And the 92 days of up time says that  
this server has been up 100% since it's been installed in colo.

However, 'top' shows a fairly high load (see below). If when I leave  
top running for a while, I see the load average spike up to  7 or 8  
occasionally. However, this doesn't translate into slow  
performance... pages still load quickly.

Also, what's up with that 157% WCPU for the mysql process? That just  
seems wrong. The WCPU number for mysql has been stuck up above 100%  
for a few weeks... it seems like something is broken there.

On my previous single processor system, top was a good rough  
indicator of how the system was doing. But it doesn't seem to work  
very well on this 8 core system.

My best guess is that the bogus mysql number is also throwing off the  
load averages, making them higher than they really are, but that's  
just a guess.

Any thoughts? Is there a better tool for measuring load?

-- John


last pid: 43730;  load averages:  1.93,  2.64,   
2.22                                           up 92+19:45:54  09:26:27
238 processes: 3 running, 235 sleeping
CPU states:  8.1% user,  0.0% nice, 17.3% system,  0.2% interrupt,  
74.4% idle
Mem: 1384M Active, 3753M Inact, 373M Wired, 884K Cache, 214M Buf,  
2150M Free
Swap: 16G Total, 88K Used, 16G Free

   PID USERNAME  THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU  
COMMAND
  1393 mysql      63  20    0   400M   221M kserel 0 191.5H 157.13%  
mysqld
43698 www         1   4    0   169M 29888K sbwait 5   0:00  2.63% httpd
43697 www         1  20    0   169M 29804K lockf  1   0:00  1.18% httpd
23376 vpopmail    1   4    0 81468K 55772K select 7   0:28  1.17%  
perl5.8.8
43729 root        1  96    0  7228K  2676K select 5   0:00  1.00%  
couriertls
43695 www         1   4    0   169M 29768K sbwait 5   0:00  0.67% httpd
43417 www         1   4    0   170M 31340K sbwait 7   0:00  0.20% httpd
85622 root        1   4    0 98588K 68764K select 5   7:54  0.20% ruby
43325 www         1  20    0   170M 30412K lockf  7   0:00  0.15% httpd
  6352 root        1   4    0 97660K 67784K select 3   1:04  0.10% ruby
42848 www         1   4    0   169M 30004K sbwait 4   0:00  0.10% httpd
43111 www         1  20    0   170M 30336K lockf  2   0:00  0.05% httpd