[petsc-dev] sm_70

[Barry Smith]

https://gitlab.com/petsc/petsc/-/merge_requests/3252 <https://gitlab.com/petsc/petsc/-/merge_requests/3252>


> On Sep 27, 2020, at 11:55 AM, Zhang, Hong <hongzhang at anl.gov> wrote:
> 
> 
> 
>> On Sep 25, 2020, at 8:09 PM, Barry Smith <bsmith at petsc.dev <mailto:bsmith at petsc.dev>> wrote:
>> 
>> 
>>   Configure by default should find out the available GPU and build for that sm_*  it should not require the user to set this (how the heck is the user going to know what to set?)  If I remember correctly there is a utility available that gives this information. 
>> 
>>   For generic builds like in package distributions I don't know how it should work, ideally all the possibilities would be available in the library and at run time the correct one will be utilized. 
> 
> 
> For package distribution we should add as many possibilities as possible. To have maximum compatibility on CUDA 11, we can add
> 
> -gencode=arch=compute_52,code=sm_52 \ 
> -gencode=arch=compute_60,code=sm_60 \ 
> -gencode=arch=compute_61,code=sm_61 \ 
> -gencode=arch=compute_70,code=sm_70 \ 
> -gencode=arch=compute_75,code=sm_75
> 
> The downside is longer compilation time and fatter binary.
> 
> Hong (Mr.)
> 
> 
> 
>> 
>>   Barry
>> 
>> 
>>> On Sep 25, 2020, at 5:49 PM, Mark Adams <mfadams at lbl.gov <mailto:mfadams at lbl.gov>> wrote:
>>> 
>>>    '--CUDAFLAGS=-arch=sm_70',
>>> 
>>> seems to fix this.
>>> 
>>> On Fri, Sep 25, 2020 at 6:31 PM Mark Adams <mfadams at lbl.gov <mailto:mfadams at lbl.gov>> wrote:
>>> I see kokkos and hyper have a sm_70 flag, but I don't see one for PETSc.
>>> 
>>> It looks like you have to specify this to get modern atomics to work in Cuda. I get:
>>> 
>>> /ccs/home/adams/petsc/include/petscaijdevice.h(99): error: no instance of overloaded function "atomicAdd" matches the argument list
>>>             argument types are: (double *, double)
>>> 
>>> I tried using a Kokkos configuration, thinking I could get these sm_70 flags, but that did not work.
>>> 
>>> Any ideas?
>>> 
>>> Mark
>> 
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20200927/3a84e85a/attachment.html>