[torqueusers] vmem and pvmem

["Mgr. Šimon Tóth"]

> Core_req       vmem  pvmem ulimit-v RPT
> =========================================
> nodes=1:ppn=2  1gb   256mb 256mb    512mb
> procs=2        1gb   256mb 256mb    1gb
> nodes=1:ppn=2  1gb   4gb   1gb      4gb
> procs=2        1gb   4gb   1gb      4gb
> nodes=1:ppn=2  1gb   -     1gb      512mb
> procs=2        1gb   -     1gb      1gb
>
> So the ulimit value that influences whether a task can allocate
> memory, is set as the lower of the vmem and pvmem values. That
> makes some sense - at least more sense than taking the larger
> value.  What doesn't make sense is allowing pvmem to be higher
> than vmem in the first place - in that case torque should probably
> reject the job or 'fix' one of the settings but leaving it as is
> might not be so bad, except for moab's behaviour (keep reading).

No. The logic is as follows:

* if pvmem (or pmem) is set
   then set the corresponding ulimit to pvmem (pmem) value

* if pvmem (or pmem) isn't set
   then set the corresponding ulimit to vmem (mem) value

Note that using pvmem is mostly pointless. On Linux this represents 
address space, not virtual memory.

You can use vmem as virtual memory, but even that is extremely confusing.

-- 
Mgr. Simon Toth