Re: [Starpu-devel] Question about MPI usage

[Xavier Lacoste <xl64100@gmail.com>]

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
>> 
>