Re: [Starpu-devel] Question about MPI usage

[Nathalie Furmento <nathalie.furmento@labri.fr>]

Hello,

That means the node has received some data for which no MPI recv has been 
posted.

Cheers,

Nathalie

On Jan 31, 17:59, Xavier Lacoste wrote:
> Hello again,
> 
> An other question,
> 
> I have factorized all my panels (counted it by hand on a small case) -- so 
> I must have performed all my updates -- and I get this error during the 
> starpu_wait_for_all() call :
> 
> [starpu][_starpu_mpi_progress_thread_func][assert failure] Number of copy 
> requests left is not zero
> 
> (The other MPI process is just waiting for something)
> 
> Any clue what it can come from ?
> Does that mean that I have received handles that I still need to use ?
> 
> Regards,
> 
> XL.
> 
> Le 31 janv. 2014 à 10:53, Xavier Lacoste <xl64100@gmail.com> a écrit :
> 
> > Nathalie,
> > 
> > Thanks for your fast answer, I forgot what was this parameter for when I 
> > copy/paste the registering code.
> > 
> > Sorry, should have read the manual again ;)
> > 
> > XL.
> > 
> > Le 31 janv. 2014 à 10:50, Nathalie Furmento <nathalie.furmento@labri.fr> 
> > a écrit :
> > 
> >> Xavier,
> >> 
> >> When you want to register a data that will be allocated only when it is 
> >> used for the first time, you need to set the "home node", the 2nd 
> >> parameter of starpu_xxx_data_register to -1.
> >> 
> >> Cheers,
> >> 
> >> Nathalie
> >> 
> >> On 31/01/2014 10:46, Xavier Lacoste wrote:
> >>> Hi,
> >>> 
> >>> I'm porting PaStiX multicore StarPU code to MPI StarPU.
> >>> I register on each node local data and halo data (data that willl be 
> >>> read used to update local data or that will be updated using local 
> >>> data).
> >>> halo data is registered using NULL pointer :
> >>> 
> >>>    starpu_matrix_data_register(&(Lhalo_handle[itercblk]), 0,
> >>>                                (uintptr_t)NULL,
> >>>                                (uint32_t)HCBLK_STRIDE(itercblk),
> >>>                                (uint32_t)HCBLK_STRIDE(itercblk),
> >>>                                HCBLK_COLNBR(itercblk),
> >>>                                sizeof(PASTIX_FLOAT));
> >>>    starpu_data_set_rank(Lhalo_handle[itercblk], HCBLK_OWNER(itercblk));
> >>>    starpu_data_set_tag(Lhalo_handle[itercblk],  HCBLK_GCBLK(itercblk));
> >>> 
> >>> On the proc that possess the data, the same data is registered with an 
> >>> allocated area (same owner/tag) :
> >>> 
> >>>    starpu_matrix_data_register(&(L_handle[itercblk]), 0,
> >>>                                (uintptr_t)SOLV_COEFTAB(itercblk),
> >>>                                (uint32_t)SOLV_STRIDE(itercblk),
> >>>                                (uint32_t)SOLV_STRIDE(itercblk),
> >>>                                CBLK_COLNBR(itercblk),
> >>>                                sizeof(PASTIX_FLOAT));
> >>>    starpu_data_set_rank(L_handle[itercblk], SOLV_PROCNUM);
> >>>    starpu_data_set_tag(L_handle[itercblk], UPDOWN_LOC2GLOB(itercblk));
> >>> 
> >>> When some tasks are submitted i get this error :
> >>> 
> >>> [starpu][_starpu_mpi_irecv_data_func][assert failure] Invalid pointer 
> >>> to receive data
> >>> 
> >>> simple: starpu_mpi.c:487: _starpu_mpi_irecv_data_func: Assertion 
> >>> `req->ptr' failed.
> >>> 
> >>> When I look into starpu_mpi.c:1422 i found that it is due to 
> >>> starpu_data_get_local_ptr() returns a NULL pointer:
> >>> 
> >>>                                        if (found_req->user_datatype == 
> >>> 0)
> >>>                                        {
> >>>                                                found_req->count = 1;
> >>>                                                found_req->ptr = 
> >>> starpu_data_get_local_ptr(found_req->data_handle);
> >>>                                                fprintf(stdout, "%s:%d 
> >>> found_req->ptr %p\n", __FILE__, __LINE__, found_req->ptr);
> >>>                                        }
> >>> 
> >>> I'm certainly doing an error somewhere, do you have any clue ? Is this 
> >>> the NULL pointer i'm giving to starpu_matrix_data_register() ?
> >>> I don't want to allocate this halo data before i need it... It should 
> >>> only update my local data and be deleted, I was hopping that StarPU was 
> >>> going to do that...
> >>> 
> >>> Any Idea of what I'm doing wrong ?
> >>> 
> >>> Regards,
> >>> 
> >>> XL.
> >>> 
> >>> PS: As we already gave all informations to starpu_mpi_task_build(), 
> >>> wouldn't it be possible to only give the task to 
> >>> starpu_mpi_task_post_build() ? That would make the code lighter :)
> >>> _______________________________________________
> >>> Starpu-devel mailing list
> >>> Starpu-devel@lists.gforge.inria.fr
> >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/starpu-devel
> >> 
> > 
> 

-- 
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Dr Nathalie Furmento                         Ingénieur de recherche CNRS
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