So Jed's "everyone" now consists of "no one" and Jed can stop complaining 
that "everyone" thinks it is a bad idea.



> On Jan 5, 2023, at 11:50 PM, Junchao Zhang <[email protected]> wrote:
> 
> 
> 
> 
> On Thu, Jan 5, 2023 at 10:32 PM Barry Smith <[email protected] 
> <mailto:[email protected]>> wrote:
>> 
>> 
>> > On Jan 5, 2023, at 3:42 PM, Jed Brown <[email protected] 
>> > <mailto:[email protected]>> wrote:
>> > 
>> > Mark Adams <[email protected] <mailto:[email protected]>> writes:
>> > 
>> >> Support of HIP and CUDA hardware together would be crazy, 
>> > 
>> > I don't think it's remotely crazy. libCEED supports both together and it's 
>> > very convenient when testing on a development machine that has one of each 
>> > brand GPU and simplifies binary distribution for us and every package that 
>> > uses us. Every day I wish PETSc could build with both simultaneously, but 
>> > everyone tells me it's silly.
>> 
>>   Not everyone at all; just a subset of everyone. Junchao is really the 
>> hold-out :-)
> I am not, instead I think we should try (I fully agree it can ease binary 
> distribution).  But satish needs to install such a machine first :)
> There are issues out of our control if we want to mix GPUs in execution.  For 
> example, how to do VexAXPY on a cuda vector and a hip vector? Shall we do it 
> on the host? Also, there are no gpu-aware MPI implementations supporting 
> messages between cuda memory and hip memory.
>> 
>>   I just don't care about "binary packages" :-); I think they are an archaic 
>> and bad way of thinking about code distribution (but yes the alternatives 
>> need lots of work to make them flawless, but I think that is where the work 
>> should go in the packaging world.)
>> 
>>    I go further and think one should be able to automatically use a CUDA 
>> vector on a HIP device as well, it is not hard in theory but requires 
>> thinking about how we handle classes and subclasses a little to make it 
>> straightforward; or perhaps Jacob has fixed that also?
>  

Reply via email to