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From: Brian Barrett (bbarrett_at_[hidden])
Date: 2007-07-14 13:59:23


On Jul 14, 2007, at 11:51 AM, Gleb Natapov wrote:

> On Sat, Jul 14, 2007 at 01:16:42PM -0400, George Bosilca wrote:
>> Instead of failing at configure time, we might want to disable the
>> threading features and the shared memory device if we detect that we
>> don't have support for atomics on a specified platform. In a non
>> threaded build, the shared memory device is the only place where we
>> need support for memory barrier. I'll look in the code to see why we
>> need support for compare-and-swap on a non threaded build.
> Proper memory barrier is also needed for openib BTL eager RDMA
> support.

Removed all the platform lists, since they won't care about this
part :).

Ah, true. The eager RDMA code should check that the preprocessor
symbol OPAL_HAVE_ATOMIC_MEM_BARRIER is 1 and disable itself if that
isn't the case. All the "sections" of ASM support (memory barriers,
locks, compare-and-swap, and atomic math) have preprocessor symbols
indicating whether support exists or not in the current build. These
should really be used :).

Brian