Re: [OMPI devel] Open-MPI build of NAMD launched from srun over 20% slowed than with mpirun
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi Ralph, On 05/09/13 12:50, Ralph Castain wrote: > Jeff and I were looking at a similar issue today and suddenly > realized that the mappings were different - i.e., what ranks are > on what nodes differs depending on how you launch. You might want > to check if that's the issue here as well. Just launch the > attached program using mpirun vs srun and check to see if the maps > are the same or not. Very interesting, the ranks to node mappings are identical in all cases (mpirun and srun for 1.6.5 and my test 1.7.3 snapshot) but what is different is as follows. For the 1.6.5 build I see mpirun report: number 0 universe size 64 universe envar 64 whereas srun report: number 1 universe size 64 universe envar NULL For the 1.7.3 snapshot both report "number 0" so the only difference there is that mpirun has: envar 64 whereas srun has: envar NULL Are these differences significant? I'm intrigued that the problem child (srun 1.6.5) is the only one where number is 1. All the best, Chris - -- Christopher SamuelSenior Systems Administrator VLSCI - Victorian Life Sciences Computation Initiative Email: sam...@unimelb.edu.au Phone: +61 (0)3 903 55545 http://www.vlsci.org.au/ http://twitter.com/vlsci -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlIoCesACgkQO2KABBYQAh+0NACeK9uyDk3UZerufAopuQRxhR/T 4skAmwS/X+8jNOPlGt4H/t5yRK8vmMer =8TGu -END PGP SIGNATURE-
Re: [OMPI devel] Open-MPI build of NAMD launched from srun over 20% slowed than with mpirun
No, nothing significant there. Afraid I've exhausted my thoughts on why the difference might exist. Anyone else care to chime in? On Sep 4, 2013, at 9:34 PM, Christopher Samuel wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA1 > > Hi Ralph, > > On 05/09/13 12:50, Ralph Castain wrote: > >> Jeff and I were looking at a similar issue today and suddenly >> realized that the mappings were different - i.e., what ranks are >> on what nodes differs depending on how you launch. You might want >> to check if that's the issue here as well. Just launch the >> attached program using mpirun vs srun and check to see if the maps >> are the same or not. > > Very interesting, the ranks to node mappings are identical in all > cases (mpirun and srun for 1.6.5 and my test 1.7.3 snapshot) but what > is different is as follows. > > > For the 1.6.5 build I see mpirun report: > > number 0 universe size 64 universe envar 64 > > whereas srun report: > > number 1 universe size 64 universe envar NULL > > > > For the 1.7.3 snapshot both report "number 0" so the only difference > there is that mpirun has: > > envar 64 > > whereas srun has: > > envar NULL > > > Are these differences significant? > > I'm intrigued that the problem child (srun 1.6.5) is the only one > where number is 1. > > All the best, > Chris > - -- > Christopher SamuelSenior Systems Administrator > VLSCI - Victorian Life Sciences Computation Initiative > Email: sam...@unimelb.edu.au Phone: +61 (0)3 903 55545 > http://www.vlsci.org.au/ http://twitter.com/vlsci > > -BEGIN PGP SIGNATURE- > Version: GnuPG v1.4.11 (GNU/Linux) > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iEYEARECAAYFAlIoCesACgkQO2KABBYQAh+0NACeK9uyDk3UZerufAopuQRxhR/T > 4skAmwS/X+8jNOPlGt4H/t5yRK8vmMer > =8TGu > -END PGP SIGNATURE- > ___ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel
Re: [OMPI devel] Open-MPI build of NAMD launched from srun over 20% slowed than with mpirun
I assume that process binding is enabled for both mpirun and srun? If not that could account for a difference between the runtimes. -Nathan From: devel [devel-boun...@open-mpi.org] on behalf of Ralph Castain [r...@open-mpi.org] Sent: Thursday, September 05, 2013 8:19 AM To: Open MPI Developers Subject: Re: [OMPI devel] Open-MPI build of NAMD launched from srun over 20% slowed than with mpirun No, nothing significant there. Afraid I've exhausted my thoughts on why the difference might exist. Anyone else care to chime in? On Sep 4, 2013, at 9:34 PM, Christopher Samuel wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA1 > > Hi Ralph, > > On 05/09/13 12:50, Ralph Castain wrote: > >> Jeff and I were looking at a similar issue today and suddenly >> realized that the mappings were different - i.e., what ranks are >> on what nodes differs depending on how you launch. You might want >> to check if that's the issue here as well. Just launch the >> attached program using mpirun vs srun and check to see if the maps >> are the same or not. > > Very interesting, the ranks to node mappings are identical in all > cases (mpirun and srun for 1.6.5 and my test 1.7.3 snapshot) but what > is different is as follows. > > > For the 1.6.5 build I see mpirun report: > > number 0 universe size 64 universe envar 64 > > whereas srun report: > > number 1 universe size 64 universe envar NULL > > > > For the 1.7.3 snapshot both report "number 0" so the only difference > there is that mpirun has: > > envar 64 > > whereas srun has: > > envar NULL > > > Are these differences significant? > > I'm intrigued that the problem child (srun 1.6.5) is the only one > where number is 1. > > All the best, > Chris > - -- > Christopher SamuelSenior Systems Administrator > VLSCI - Victorian Life Sciences Computation Initiative > Email: sam...@unimelb.edu.au Phone: +61 (0)3 903 55545 > http://www.vlsci.org.au/ http://twitter.com/vlsci > > -BEGIN PGP SIGNATURE- > Version: GnuPG v1.4.11 (GNU/Linux) > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iEYEARECAAYFAlIoCesACgkQO2KABBYQAh+0NACeK9uyDk3UZerufAopuQRxhR/T > 4skAmwS/X+8jNOPlGt4H/t5yRK8vmMer > =8TGu > -END PGP SIGNATURE- > ___ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel ___ devel mailing list de...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/devel
