Hi Pavan, thank you for your answer. I get this output: larcher@na75:> HYDRA_TOPO_DEBUG=1 mpiexec -n 8 -bind-to hwthread -map-by core /bin/true | sort process 0 binding: 1 0 0 0 0 0 0 0 process 1 binding: 0 1 0 0 0 0 0 0 process 2 binding: 0 0 1 0 0 0 0 0 process 3 binding: 0 0 0 1 0 0 0 0 process 4 binding: 0 0 0 0 1 0 0 0 process 5 binding: 0 0 0 0 0 1 0 0 process 6 binding: 0 0 0 0 0 0 1 0 process 7 binding: 0 0 0 0 0 0 0 1 larcher@na75:> HYDRA_TOPO_DEBUG=1 mpiexec -n 4 -bind-to hwthread -map-by core /bin/true | sort process 0 binding: 1 0 0 0 0 0 0 0 process 1 binding: 0 1 0 0 0 0 0 0 process 2 binding: 0 0 1 0 0 0 0 0 process 3 binding: 0 0 0 1 0 0 0 0 which is exactly what I need, thank you ! Also passing -bind-to core:1 is suitable. Best, Aurelien On Wed, Apr 1, 2015 at 7:28 PM, Balaji, Pavan <[email protected]> wrote:
Try this:
HYDRA_TOPO_DEBUG=1 mpiexec -n 8 -bind-to hwthread -map-by core /bin/true | sort
-- Pavan
On Apr 1, 2015, at 12:26 PM, Balaji, Pavan <[email protected]> wrote:
This is not linux specific. It's following whatever order the OS gives it. You might want to look at the -map-by option for better controlling the processes in the way you are looking for.
-- Pavan
On Apr 1, 2015, at 11:47 AM, Aurélien Larcher < [email protected]> wrote:
Hi Rajeev, thank you for the pointer, actually this page leads me to another question. What is exactly the policy for binding by hwthreads ?
I can see that:
larcher@na75:> HYDRA_TOPO_DEBUG=1 mpiexec -n 8 -bind-to hwthread /bin/true | sort process 0 binding: 1 0 0 0 0 0 0 0 process 1 binding: 0 0 0 0 1 0 0 0 process 2 binding: 0 1 0 0 0 0 0 0 process 3 binding: 0 0 0 0 0 1 0 0 process 4 binding: 0 0 1 0 0 0 0 0 process 5 binding: 0 0 0 0 0 0 1 0 process 6 binding: 0 0 0 1 0 0 0 0 process 7 binding: 0 0 0 0 0 0 0 1
Which seems unfortunate because since the processor is a quad core with hyperthreading the same physical core will get the first two threads.
larcher@na75:> psrinfo -pv The physical processor has 4 cores and 8 virtual processors (0-7) The core has 2 virtual processors (0 4) The core has 2 virtual processors (1 5) The core has 2 virtual processors (2 6) The core has 2 virtual processors (3 7) x86 (GenuineIntel 206A7 family 6 model 42 step 7 clock 3392 MHz) Intel(r) Core(tm) i7-2600 CPU @ 3.40GHz
This is confirmed by:
HYDRA_TOPO_DEBUG=1 mpiexec -n 4 -bind-to hwthread /bin/true | sort process 0 binding: 1 0 0 0 0 0 0 0 process 1 binding: 0 0 0 0 1 0 0 0 process 2 binding: 0 1 0 0 0 0 0 0 process 3 binding: 0 0 0 0 0 1 0 0
Is it due to a Linux-specific numbering of logical cores ?
Thank you,
Aurelien
On Wed, Apr 1, 2015 at 6:18 PM, Thakur, Rajeev <[email protected]> wrote: Yes, see https://wiki.mpich.org/mpich/index.php/Using_the_Hydra_Process_Manager#Proce...
Rajeev
On Apr 1, 2015, at 11:14 AM, Aurélien Larcher < [email protected]> wrote:
Hi, running parallel code on my workstation (with OpenIndiana) I discovered that MPI processes were migrated on a regular basis from one core to another.
On SunOS systems the command 'pbind' allows binding a process to a specific core. So I am wondering if binding automatically each process to the next available core is supported directly from MPICH ?
Best regards
Aurelien
--
LARCHER Aurélien | KTH, School of Computer Science and Communication Work: +46 (0) 8 790 71 42 | Lindstedtsvägen 5, Plan 4, 100 44 Stockholm, SWEDEN
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--
LARCHER Aurélien | KTH, School of Computer Science and Communication Work: +46 (0) 8 790 71 42 | Lindstedtsvägen 5, Plan 4, 100 44 Stockholm, SWEDEN
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-- Pavan Balaji ✉️ http://www.mcs.anl.gov/~balaji
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-- Pavan Balaji ✉️ http://www.mcs.anl.gov/~balaji
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-- ------------------------------------------------------------------------------- LARCHER Aurélien | KTH, School of Computer Science and Communication Work: +46 (0) 8 790 71 42 | Lindstedtsvägen 5, Plan 4, 100 44 Stockholm, SWEDEN ------------------------------------------------------------------------------- _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss