[petsc-dev] Non-scalable matrix operations

[Matthew Knepley]

On Fri, Dec 23, 2011 at 12:55 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> On Fri, Dec 23, 2011 at 12:27, Mark F. Adams <mark.adams at columbia.edu>wrote:
>
>> A more interesting thing is partition down to the thread level and keep
>> about 100 vertices per thread (this might be to big for a GPU...)
>
>
> It's fine to have more partitions than threads.
>
>
>> and then use locks of some sort for the shared memory synchronization
>
>
> It can be lock-free, your thread just waits until a buffer has been marked
> as updated. Since the reader/writer relationships are predefined, it's not
> actually a lock. (You can do more general methods lock-free too.)
>

You could use

  a) coloring and stream events (easy)

  b) what John Cohen does which I still do not understand

We should talk to him

   Matt

>
>



-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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