On Wed, Mar 13, 2013 at 02:46:34PM -0500, Quincey Koziol wrote:
Can something be done with generalized request? Someone always brings this up. :-) We should get up to speed on the GRQ routines and know what they can do...
They cannot do much. I am, reluctantly, the worlds expert on generalized requests, having written a paper about it 5(!!!) years ago. http://dx.doi.org/10.1007/978-3-540-75416-9_33 pdf: http://www.mcs.anl.gov/~robl/papers/latham_grequest-enhance.pdf Standard Generalized requests have a "all progress must happen outside of MPI" progress model. Perhaps in this modern surfeit of cores era, it is no longer a big deal to spawn a thread ? The paper I linked proposes generalized request extensions designed to play better with posix, pvfs, and NTFS async i/o routines. These routines can make progress in the background, but do need someone to call a completion function (aio_suspend, PVFS_sys_wait, or WaitForMultipleObjectEx). ==rob -- Rob Latham Mathematics and Computer Science Division Argonne National Lab, IL USA