[Mauiusers] Maui allocation problems.
bill at Princeton.EDU
Thu Dec 27 07:28:44 MST 2007
Problem: #PBS -l nodes=124:ppn=1+66:ppn=2 doesn't work as I'd like it to.
Maui is setup to alloacate in a worstfit way to spread jobs across nodes
based on a JOBCOUNT priority.
NODECFG[DEFAULT] PRIORITYF='-10 * JOBCOUNT'
It is also set up to allocate as the user specifies:
This all works as expected.
The problem is that these single core jobs end up filling up initially
empty nodes instead of being allocated across nodes with only 1 job
running, which is the desired allocation. What appears to be happening
is that PBS sends the list of nodes to maui which then takes this static
view of things and starts allocating. Since there are empty nodes and
nodes with 1 core being used, those empty nodes always get filled with
theses single core requests instead of being allocated to a node with
one core being used. What winds up happening is that the empty nodes
gets filled completely (all 4 cores) while these initially almost empty
nodes never get another core allocated. What I expected to happen was
that as the nodes are being allocated to jobs, their job count would
change and thus some of these already allocated nodes would also join in
this allocation pool as their jobcounts would now be equal. And in all
cases, before a third core would be used on one of these initially empty
nodes, a second core would be used on these other nodes.
Is this possible in any way?
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