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 >
