TOP shows above 100% WCPU usage
Bill LeFebvre
bill at lefebvre.org
Thu Aug 17 05:28:12 UTC 2006
Mike Jakubik wrote:
> Dan Nelson wrote:
>>> How can mysql use 160%? Is this a reporting bug in top because mysql
>>> is threaded?
>>>
>>
>> You have multiple CPUs, so a threaded process can theoretically reach
>> 100*ncpus cpu usage.
>>
>>
>
> Ahh, thats makes sense, thanks.
Actually it doesn't. IMO, %CPU should be biased for all available cpu, not
just a single cpu. In other words, a single-threaded process running on a
two processor box should never see more than 50% cpu. That's how top
computes it for SunOS. But for freebsd top only displays whats in the proc
structure and I don't know off-hand how the kernel records it.
Bill LeFebvre
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