Core Duo - only one cpu being used

[Eric Anderson]

Scott Long wrote:
> Erich Dollansky wrote:
>> Hi,
>>
>> Eric Anderson wrote:
>>
>>> Erich Dollansky wrote:
>>>
>>>> Hi,
>>>>
>>>> Eric Anderson wrote:
>>>>
>>>>>
>>>>>   PID USERNAME    THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU 
>>>>> COMMAND
>>>>>    11 root          1 171   52     0K     8K CPU1   0   0:00 99.02% 
>>>>> idle: cpu1
>>>>>  2653 root          1 128    0 18564K 17560K RUN    0   0:01 34.00% 
>>>>> cc1plus
>>>>
>>>>
>>>> could it be that it is just a problem with top itself?
>>>>
>>>> It cannot be that CPU1 uses 99% for the idle process and 34% for the 
>>>> compiler.
>>>>
>>>> Play with the other sort options. You might find the the idle 
>>>> process for CPU0.
>>>
>>>
>>> Is this what you want:
>>>
>>> $ ps -auxw | grep idle
>>> root        11 99.0  0.0     0     8  ??  RL     7:45PM   0:00.00 
>>> [idle: cpu1]
>>> root        12  0.0  0.0     0     8  ??  RL     7:45PM  51:04.57 
>>> [idle: cpu0]
>>>
>> something is really wrong here. CPU1 gets 99% of the time but uses 
>> then only 0 seconds while CPU0 gets 0% of the time but uses 51 hours?
> 
> CPU1 is being treated as a hyperthreading core instead of a real core, 
> and is being disabled per our policy on Intel hyperthreading.  By 
> 'disabled' I mean that it is started, but it is being excluded from
> scheduling decisions, and thus is only running its idle proc.  It's
> also handling any interrupts that come to it, such as timer and IPI
> interrupts, so it's at 99% instead of 100% for the idle proc.  There
> is nothing broken about the number you are seeing, your system is
> just running under a scheduling policy that it should not be.
> 
> This should have been fixed a week or so ago by a commit to HEAD,
> RELENG_6, and RELENG_6_1 by Colin Percival.  How old is kernel?


6.1-RC FreeBSD 6.1-RC #13: Thu Apr 27 08:33:14 CDT 2006

So I probably just missed it.  I'll rebuilt and try it tomorrow morning, 
and report back.

Thanks for all the help and a good description.

Eric



-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.
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