Claudio
And so what is a "group of processes (tasks)" ?
TileSize specifies the unit that should be used when partitioning the processes across the nodes. For example, TileSize=2 ProcessCount=8 means that the 8 processes should be partitioned across nodes in tiles (units) of 2; for a total of 4 tiles. If [ResourceCount=4] then each node would receive 1 tile (2 processes). If [ResourceCount=3] then one of the nodes would receive 2 tiles and the other two nodes 1 tile each. (It would not be possible to partition the processes as two nodes receiving 3 processes and one node 2 processes.)
Is there a way to specify "threads per task (process)" ?
Not directly. You can specify the number of cpus to be equal to or more than the threads that your application will use. To use your example: ProcessCount=3 CpuCount=8 ResourceCount=2 See also some examples that Michel send out last December http://www-unix.gridforum.org/mail_archive/jsdl-wg/2004/12/msg00006.html I am working (ever so slowly) on a revision of the ProcessTopology section for the specification. Hopefully it will be ready for review early next week. Thanks. Andreas claudio cacciari wrote:
Dear All,
I 'm trying to understand the meaning of TileSize and ProcessCount elements to describe a MPI + OpenMPI job. For example, in a job submission request for a batch scheduler (LoadLeveler, PBS and so on) I can specify :
tasks per job=3 threads per task=4 processors per task=4
in order to get 1 thread per processor ( processors per task = threads per task ). I can set "nodes per job"=2 (with a a configuration of 8 cpus per node) or leave the scheduler sets this value. For what I understand in JSDL there are :
[tileSize] tasks (processes) per group [ProcessCount] tasks (processes) per job [CPUCount] processors per job (with ResourceCount=1) [CPUCount + ResourceCount] processors per node + nodes per job
from which I can get :
tasks per job = [ProcessCount] = 3 threads per task = [ ? ] = 4 processors per task = [ CPUCount * ResourceCount / ProcessCount ] = 4 nodes per job = [ ResourceCount ] = 2
And so what is a "group of processes (tasks)" ? Is there a way to specify "threads per task (process)" ?
Best Regards, Claudio Cacciari
========================================================= Claudio Cacciari CINECA - Via Magnanelli 6/3 40033 High Performance System Group Casalecchio di Reno - Bologna - ITALY e-mail: c.cacciari@cineca.it http://www.cineca.it Tel: 051/6171411 - Fax: 051/6132198 =========================================================
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