[torqueusers] Re: Memory Limits with torque/maui & enforcement

Tom Pierce thpierce at gmail.com
Sun Sep 21 17:20:47 MDT 2008


> Åke Sandgren wrote:
>
> On Thu, 2008-09-18 at 13:18 -0600, Josh Butikofer wrote:
>
>>>You may want to use pvmem as opposed to just pmem. Sometimes Linux has a hard time enforcing pmem
>>>because of the way it handles virtual memory. In my experience, pvmem behaves more as expected. I
>>>would try both out and see which seems to work better in your case.>>
>
>
>>To be specific the linux kernel does NOT enforce pmem (RLIMIT_RSS,
>>ulimit -m) at all. There was pieces of such code in the kernel up to
>> 2.4.15 or so when they removed it completely.
>>There is still no such code in at least the 2.6 based kernels.



 So to have torque manage the memeory needs of a parallel job, I need to use
 #PBS -l nodes=2:ppn=4, pvmem=1500m     would require that a node have
 4 processors, and that each process needs 1500 megabytes of memory, so
 the node would have to have 4*1500 = 6000m or 6 Gb per node BEFORE it
 would "qualify" the node as having adequate resources to run. And then
 if the node only had 6 Gb of physical memory, the next job would have
 to wait for this node to be freed-up.

  Is that how torque resource manager works with the memory requirement?
  or does pvmem allow for swap space as well?

-----------------------
Thanks

Tom


More information about the torqueusers mailing list