The overall design in OMPI was that no OMPI module should be allowed to decide if threads are on (thus it should not rely on the value returned by opal_using_threads during it's initialization stage). Instead, they should respect the level of thread support requested as an argument during the initialization step.
And this is true even for the BTLs. The PML component init function is propagating the enable_progress_threads and enable_mpi_threads, down to the BML, and then to the BTL. This 2 variables, enable_progress_threads and enable_mpi_threads, are exactly what the ompi_mpi_init is using to compute the the value of the opal) using_thread (and that this patch moved). The setting of the opal_using_threads was delayed during the initialization to ensure that it's value was not used to select a specific thread-level in any module, a behavior that is allowed now with the new setting. A drastic change in behavior... George. On Tue, Dec 9, 2014 at 3:33 AM, Ralph Castain <r...@open-mpi.org> wrote: > Kewl - I’ll fix. Thanks! > > On Dec 9, 2014, at 12:32 AM, Pascal Deveze <pascal.dev...@bull.net> wrote: > > Hi Ralph, > > This in in the trunk. > > *De :* devel [mailto:devel-boun...@open-mpi.org > <devel-boun...@open-mpi.org>] *De la part de* Ralph Castain > *Envoyé :* mardi 9 décembre 2014 09:32 > *À :* Open MPI Developers > *Objet :* Re: [OMPI devel] Patch proposed: opal_set_using_threads(true) > in ompi/runtime/ompi_mpi_init.c is called to late > > Hi Pascal > > Is this in the trunk or in the 1.8 series (or both)? > > > > On Dec 9, 2014, at 12:28 AM, Pascal Deveze <pascal.dev...@bull.net> wrote: > > > In case where MPI is compiled with --enable-mpi-thread-multiple, a call to > opal_using_threads() always returns 0 in the routine > btl_xxx_component_init() of the BTLs, event if the application calls > MPI_Init_thread() with MPI_THREAD_MULTIPLE. > > This is because opal_set_using_threads(true) in > ompi/runtime/ompi_mpi_init.c is called to late. > > I propose the following patch that solves the problem for me: > > diff --git a/ompi/runtime/ompi_mpi_init.c b/ompi/runtime/ompi_mpi_init.c > index 35509cf..c2370fc 100644 > --- a/ompi/runtime/ompi_mpi_init.c > +++ b/ompi/runtime/ompi_mpi_init.c > @@ -512,6 +512,13 @@ int ompi_mpi_init(int argc, char **argv, int > requested, int *provided) > } > #endif > > + /* If thread support was enabled, then setup OPAL to allow for > + them. */ > + if ((OPAL_ENABLE_PROGRESS_THREADS == 1) || > + (*provided != MPI_THREAD_SINGLE)) { > + opal_set_using_threads(true); > + } > + > /* initialize datatypes. This step should be done early as it will > * create the local convertor and local arch used in the proc > * init. > @@ -724,13 +731,6 @@ int ompi_mpi_init(int argc, char **argv, int > requested, int *provided) > goto error; > } > > - /* If thread support was enabled, then setup OPAL to allow for > - them. */ > - if ((OPAL_ENABLE_PROGRESS_THREADS == 1) || > - (*provided != MPI_THREAD_SINGLE)) { > - opal_set_using_threads(true); > - } > - > /* start PML/BTL's */ > ret = MCA_PML_CALL(enable(true)); > if( OMPI_SUCCESS != ret ) { > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2014/12/16459.php > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2014/12/16462.php > > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2014/12/16463.php >
