Thanks Rob very much, Jialin On Fri, Oct 17, 2014 at 9:45 AM, Rob Latham <[email protected]> wrote:
On 10/16/2014 10:07 PM, Jaln wrote:
Hi, How can I know the aggregator's rank in the collective I/O?
fd->hints->ranklist[] contains an array of MPI ranks assigned to an aggregator.
I also feel difficult to distinguish the aggregator and non-aggregator
in the ad_read_coll.c, for example, in function ADIOI_R_Exchange_data, how can I know it is executed by a process or an aggregator? I can only see how 'nprocs_for_coll' is used in partitioning the file domain, but couldn't see how it is used to tell the certain number of aggregator to do the collective I/O.
I think you want to look at ADIOI_Calc_aggregator, which will report which MPI-IO aggregator is responsible for which regions of a file, and how much.
ADIOI_R_Exchange_data is called by every process. Some processes are receiving data from an aggregator, and aggregators are sending read data, but everyone participates.
Take a look earlier on: ADIOI_Calc_my_req and ADIOI_Calc_others_req are two of the routines responsible for generating the schedule of requests.
==rob
-- Rob Latham Mathematics and Computer Science Division Argonne National Lab, IL USA _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss
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