[NTLUG:Discuss] linux on dual cpu

[Patrick R. Michaud]

On Thu, Sep 14, 2006 at 10:25:24AM -0500, Fred James wrote:
> All
> I put Mandrake 10.1 on an old Dell Dual CPU Power Edge (forgot the 
> number just now) - the hardware list (Mandrake control) sees both 
> processors.  Is it safe to assume both are being used?

You might try the top(1) command, and then press "1" when it's
running to toggle the cpu display.  If you see something like

Tasks: 111 total,   2 running, 109 sleeping,   0 stopped,   0 zombie
Cpu0  :  0.0% us,  0.1% sy,  0.0% ni, 99.3% id,  0.6% wa,  0.0% hi,  0.0% si
Cpu1  :  0.0% us,  0.0% sy,  0.0% ni, 100.0% id,  0.0% wa,  0.0% hi,  0.0% si

then I bet that both CPUs are being used.  


However, if the CPUs are running with hyperthreading enabled, then 
you may see four cpu lines -- for example, here's what I get from top(1)
on my old PowerEdge dual-CPU server:

Tasks: 317 total,   1 running, 316 sleeping,   0 stopped,   0 zombie
Cpu0  :  0.0% us,  0.3% sy,  0.0% ni, 99.7% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu1  :  0.7% us,  0.7% sy,  0.0% ni, 98.7% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu2  :  0.0% us,  0.0% sy,  0.0% ni, 100.0% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu3  :  0.0% us,  0.0% sy,  0.0% ni, 100.0% id,  0.0% wa,  0.0% hi,  0.0% si

Running "cat /proc/cpuinfo" also provides some clues.

Hope this helps.

Pm