I think this is a good discussion for the Dallas meeting. We can hold off on this RFC until then.
-Nathan On Tue, Jan 06, 2015 at 06:16:39PM -0500, George Bosilca wrote: > On Tue, Jan 6, 2015 at 4:25 PM, Jeff Squyres (jsquyres) > <jsquy...@cisco.com> wrote: > > My enthusiasm for this was primarily because I thought we had talked > about exactly this issue before (at the last meeting in Chicago?), and > decided that the option is useless -- in part, because it always *must* > be enabled for shared memory correctness. > > Is that incorrect? > > This is correct. We need the memory fences and atomic operations for > shared memory in all cases. When thread support is enabled we also need > them in various other places. However, this option also turns on the lock > prefix for the atomic operations, forcing them to always be atomic. I am > not sure that this has no unexpected side-effects on the code. > George. > > > On Jan 6, 2015, at 4:12 PM, George Bosilca <bosi...@icl.utk.edu> wrote: > > > Successive alteration of the build system made this option less > relevant and especially less meaningful. However, while removing it > sounds like a desirable cleanup, we have to keep in mind that this will > enable all locks and all memory barriers even in cases where they are > not necessary (via OPAL_WANT_SMP_LOCKS). > > > > Thus, I do not share the enthusiasm of the others. I would prefer to > see an evaluation of the impact on performance, a patch and a little bit > more than 1/2 a day to react to it (the proposed deadline seems to be > today January 6th) before such a drastic change. > > > > George. > > > > > > On Tue, Jan 6, 2015 at 12:05 PM, Ralph Castain <r...@open-mpi.org> > wrote: > > +1 > > > > > On Jan 6, 2015, at 9:04 AM, Jeff Squyres (jsquyres) > <jsquy...@cisco.com> wrote: > > > > > > +1 > > > > > > On Jan 6, 2015, at 11:55 AM, Howard Pritchard <hpprit...@gmail.com> > wrote: > > > > > >> I agree. Please remove this config option. > > >> > > >> 2015-01-06 9:44 GMT-07:00 Nathan Hjelm <hje...@lanl.gov>: > > >> > > >> What: Remove the --disable-smp-locks configure option from master. > > >> > > >> Why: Use of this option produces incorrect results/undefined > behavior > > >> when any shared memory BTL is in use. Since BTL usage is enabled > even > > >> when using cm for point-to-point this option can never be safely > used. > > >> > > >> When: Thurs, Jan 6, 2015 > > >> > > >> -Nathan > > >> > > >> _______________________________________________ > > >> devel mailing list > > >> de...@open-mpi.org > > >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > > >> Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/01/16736.php > > >> > > >> _______________________________________________ > > >> devel mailing list > > >> de...@open-mpi.org > > >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > > >> Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/01/16737.php > > > > > > > > > -- > > > Jeff Squyres > > > jsquy...@cisco.com > > > For corporate legal information go to: > http://www.cisco.com/web/about/doing_business/legal/cri/ > > > > > > _______________________________________________ > > > devel mailing list > > > de...@open-mpi.org > > > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/01/16739.php > > > > _______________________________________________ > > devel mailing list > > de...@open-mpi.org > > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > > Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/01/16740.php > > > > _______________________________________________ > > devel mailing list > > de...@open-mpi.org > > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > > Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/01/16741.php > > -- > Jeff Squyres > jsquy...@cisco.com > For corporate legal information go to: > http://www.cisco.com/web/about/doing_business/legal/cri/ > > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/01/16742.php > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2015/01/16743.php
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