Re: Scheduling with Hyperthreading

[Mike Sullivan <mike.sullivan@alltec.com>]

  Mark

I would to a quick snap with top, and when I saw 99.9% I assumed the the 
process had
been there during the time top was starting up.

Looking at /proc/(pid)/cpu, shows that with two jobs running they are 
sticking to cpu 0 and 1
which are siblings


                                                                        
                                                                        
Regards
                                                                        
                                                                        Mike

Mark Hahn wrote:

>>that if I run two compute intensive jobs on a Dual Xeon, the processes 
>>run on separate
>>physical cpus and can spend a significant amount of time with both on a 
>>single
>>cpu.
>>    
>>
>
>how did you determine this?  running another program, such as top,
>will naturally disturb the scheduler and corrupt any observations.
>the only means I can think of is to look in /proc/<pid>/cpu near
>very infrequently (ideally, just before the processes exit.)
>or is this what you've done?
>  
>

-- 
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Mike Sullivan                           Director Performance Computing
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