On Apr 26, 2013, at 7:40 PM, Orion Poplawski <or...@cora.nwra.com> wrote:
> On 04/25/2013 04:48 AM, Jeff Squyres (jsquyres) wrote: >> Orion -- >> >> I would just caution against using Open MPI with a thread-enabled libevent. >> In most cases, the performance impact wouldn't matter, but the whole point >> of MPI is to be high performance. The current 1.7 series does *not* use a >> thread-enabled libevent because it detracts from performance. Hence, using >> a thread-enabled libevent detracts from Open MPI's main purpose. >> >> If Open MPI is suddenly bundled with a thread-enabled libevent, *performance >> will go down* and users will be unhappy. We have learned painfully over the >> years that users expect good performance out of the box -- if they have get >> "bad" performance out of the box and have to do something special to enable >> "good" performance, they'll be annoyed and blame Open MPI. >> >> So I would request that you do *not* link Open MPI against a thread-enabled >> libevent until we are able integrate such functionality properly, and take >> measures to mitigate the performance implications (which likely won't be >> until at least the 1.9 series). > > So, the Fedora Packaging committee has taken that part to heart, but not the > bundling: > > * Bundling exception for libevent in openmpi - > https://fedorahosted.org/fpc/ticket/273 (spot, 16:16:52) > * ACTION: FPC is pretty universally against this bundling, spot will > try to make a libevent-nothread.so and update libevent. (spot, > 16:26:38) Just for clarification: who or what is "spot"? > > So it looks like I will need to shortly be looking at how to link against an > external libevent. Any help with that would be greatly appreciated. As I said, I'll take a look at it, but can't commit to having it available any time soon. It isn't something I would suggest someone try who isn't fully versed in OMPI's code base. > > -- > Orion Poplawski > Technical Manager 303-415-9701 x222 > NWRA/CoRA Division FAX: 303-415-9702 > 3380 Mitchell Lane or...@cora.nwra.com > Boulder, CO 80301 http://www.cora.nwra.com > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel
