Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

Subject: Re: [OMPI devel] malloc(0) warnings
From: George Bosilca (bosilca_at_[hidden])
Date: 2010-05-06 15:36:08


This is an artifact of using the gatherv (or the scatterv) on an inter-communicator without any useful data (i.e. either count of zero or empty datatypes). Looks more like a synchronization than a real operation.

  george.

On May 5, 2010, at 20:17 , Lisandro Dalcin wrote:

> After building 1.4.2 with debug flags to configure, I get this (I've
> got these warnings in previous releases, too):
>
> malloc debug: Request for 0 bytes (coll_inter_gatherv.c, 94)
> malloc debug: Request for 0 bytes (coll_inter_gatherv.c, 94)
> malloc debug: Request for 0 bytes (coll_inter_gatherv.c, 94)
> malloc debug: Request for 0 bytes (coll_inter_gatherv.c, 94)
>
> malloc debug: Request for 0 bytes (coll_inter_scatterv.c, 82)
> malloc debug: Request for 0 bytes (coll_inter_scatterv.c, 82)
> malloc debug: Request for 0 bytes (coll_inter_scatterv.c, 82)
> malloc debug: Request for 0 bytes (coll_inter_scatterv.c, 82)
>
>
> --
> Lisandro Dalcin
> ---------------
> CIMEC (INTEC/CONICET-UNL)
> Predio CONICET-Santa Fe
> Colectora RN 168 Km 472, Paraje El Pozo
> Tel: +54-342-4511594 (ext 1011)
> Tel/Fax: +54-342-4511169
> _______________________________________________
> devel mailing list
> devel_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/devel