Re: [Beowulf] Strange SGE scheduling problem

[Reuti]

Hi,

Am 22.07.2008 um 23:54 schrieb Schoenefeld, Keith:

My cluster has 8 slots (cores)/node in the form of two quad-core
processors. Only recently we've started running jobs on it that  
require
12 slots.  We've noticed significant speed problems running  
multiple 12
slot jobs, and quickly discovered that the node that was running 4  
slots
on one job and 4 slots on another job was running both jobs on the  
same
processor cores (i.e. both job1 and job2 were running on CPU's #0-#3,
and the CPUs #4-#7 were left idling.  The result is that the jobs were
competing for time on half the processors that were available.

how did you check this? With `top`? You have one queue with 8 slots  
per machine?

-- Reuti

In addition, a 4 slot job started well after the 12 slot job has  
ramped
up results in the same problem (both the 12 slot job and the four slot
job get assigned to the same slots on a given node).

Any insight as to what is occurring here and how I could prevent it  
from
happening?  We were are using SGE + mvapich 1.0 and a PE that has the
$fill_up allocation rule.

I have also posted this question to the [EMAIL PROTECTED]
mailing list, so my apologies for people who get this email multiple
times.

Any help is appreciated.

-- KS

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