[ALPS-users] execution time of example/parapack/exchange

[Synge Todo]

Dear Dominik,

The parapack scheduler supports parallel workers.
You can run the exchange worker in parallel by using multiple threads or processes provided that

1. the parameters are given by XML files instead of the standard input, and
    (running with standard input is for debugging or testing)
2. multiple threads are assigned to each worker by using -p (--threads-per-clone) option
    (default is -p 1).

Please try, e.g.,

$ parameter2xml exchange.ip
$ mpirun -np 4 ./exchange --mpi --threads-per-clone 4 exchange.ip.in.xml

Best,
Synge


> From: Dominik Schildknecht <dominik.schildknecht at psi.ch>
> Subject: [ALPS-users] execution time of example/parapack/exchange
> Date: 16 May 2017 at 01:48:28 GMT-7
> To: <comp-phys-alps-users at lists.phys.ethz.ch>
> Reply-To: comp-phys-alps-users at lists.phys.ethz.ch
> 
> Dear all,
> 
> I was testing your example in example/parapack/exchange with the
> exchange.ip modified to only test the ising case, however with more
> sweeps, to test the time spent.
> 
> I know that the parallel_exchange_worker gets called (visible via the
> line "EXMC: number of replicas on each process = 2 2", which will only
> be outputted by the parallel_exchange_worker). I would by this output
> assume that different replicas get distributed over the cores,.
> 
> The time spent in the simulation however stays the same irrespective of
> the number of processes I provide to MPI or not even call the MPI
> library at all.
> 
> I call the function in the following way:
> 
>    mpirun -np 2 ./exchange --mpi < exchange.ip
> 
> resp.
> 
>    ./exchange < exchange.ip
> 
> Do I miss an important argument in the input file / command line
> argument, that prevents the parallel execution of replicas?
> 
> Best,
> Dominik
> 
> -- 
> Paul Scherrer Institut
> Dominik Schildknecht
> PhD Student
> WHGA/129
> CH-5232 Villigen-PSI
> Phone: +41 56 310 55 68
> 
> 
> 
> 
> ----
> Comp-phys-alps-users Mailing List for the ALPS Project
> http://alps.comp-phys.org/
> 
> List info: https://lists.phys.ethz.ch//listinfo/comp-phys-alps-users
> Archive: https://lists.phys.ethz.ch//pipermail/comp-phys-alps-users
> 
> Unsubscribe by writing a mail to comp-phys-alps-users-leave at lists.phys.ethz.ch.
>