[Mpi3-hybridpm] Hybrid WG meeting at the Forum

[Ron Brightwell]

On 12/06/2010 05:59 PM, James Dinan wrote:
> On 12/6/10 5:49 PM, Pavan Balaji wrote:
>> Hi Doug,
>>
>> On 12/06/2010 11:42 AM, Douglas Miller wrote:
>>> Re: SHMEM ALLOC: I thought we were considering adding a "const char
>>> *key" param so that shared memory allocations better match OS (e.g.
>>> POSIX) shmem allocations and also to allow the call to be
>>> non-synchronizing.
>>
>> As I recalled, this was still being discussed. Did we decide on adding
>> the key? Ron?
>>
>> I'll add it in as a discussion item.
>
> I think that the key is primarily helpful as a bootstrap mechanism for
> processes to ensure they connect to the right shared segment.  I think
> the intent was to have shmem alloc be collective so this should be
> extraneous.

Right. I think you lose several important optimizations for shared 
memory if the call is not collective. It doesn't have to be synchronous, 
but it does have to be collective.

-Ron