[petsc-dev] usage of Malloc2 at VecScatterCopy_MPI_ToAll

[Barry Smith]

On Jul 9, 2010, at 8:14 PM, Lisandro Dalcin wrote:

> On 9 July 2010 22:07, Barry Smith <bsmith at mcs.anl.gov> wrote:
>> 
>>  Hmm, looks like we could use a Malloc3() there :-) Even better.
>> 
> 
> Is this safe regarding memory alignment?
> 

    Yes, Jed fixed it so everything in the MallocX() is aligned.

   Barry

>> 
>>   Barry
>> 
>> On Jul 9, 2010, at 8:00 PM, Lisandro Dalcin wrote:
>> 
>>> On 9 July 2010 21:26, Barry Smith <bsmith at mcs.anl.gov> wrote:
>>>> 
>>>>  I consider this bogus warnings.
>>>> 
>>> 
>>> I agree on that. My point is the actual usage of Malloc2.
>>> 
>>>  ierr                =
>>> PetscMalloc2(1,VecScatter_MPI_ToAll,&sto,size,PetscMPIInt,&sto->count);CHKERRQ(ierr);
>>>  ierr                =
>>> PetscMalloc(size*sizeof(PetscMPIInt),&sto->displx);CHKERRQ(ierr);
>>> 
>>> What's the point of allocating 1 struct + size ints, and next size
>>> more ints? I would use Malloc for the struct, and then Malloc2 for the
>>> two arrays.
>>> 
>>> 
>>>>   Barry
>>>> 
>>>> On Jul 9, 2010, at 7:22 PM, Lisandro Dalcin wrote:
>>>> 
>>>>> While building with nvcc, I looked at this warning:
>>>>> 
>>>>> libfast in: /usr/local/petsc/dev/src/vec/vec/utils
>>>>> vscat.c(322): warning: variable "sto" is used before its value is set
>>>>> 
>>>>> Do we really need to use Malloc2 in such line? Perhaps we should
>>>>> actually use Malloc2 for sto->count and sto->displx ?
>>>>> 
>>>>> --
>>>>> 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
>>>> 
>>>> 
>>> 
>>> 
>>> 
>>> --
>>> 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
>> 
>> 
> 
> 
> 
> -- 
> 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