[mpich-discuss] MPICH2 (or MPI_Init) limitation | scalability

[Bernard Chambon]

Hello,

Good news, It works !
Whith your patch I can run 255 tasks and perhaps more, without any special
configuration on the machine (*)


It's a very good news for me,  Let me thank you very much Darius

>mpiexec -np 255 bin/advance_test 
Running MPI version 2, subversion 2 
I am the master task 0 sur ccwpge0062, for 254 slaves tasks, we will exchange a buffer of 10 MB

slave number 1, iteration = 1
slave number 2, iteration = 1
slave number 3, iteration = 1
...
slave number 254, iteration = 1
slave number 1, iteration = 2
slave number 2, iteration = 2
...

slave number 254, iteration = 7


Now will try to run jobs (thru GridEngine + Hydra) with higher numbers of tasks
and I will tell you if it's ok

Best regards


Le 11 janv. 2012 à 18:49, Darius Buntinas a écrit :

> I think I found the problem.  Apply this patch (using "patch -p0 < seg_sz.patch"), then "make clean; make; make install", and try it again.  Make sure to relink your application.
> 
> Let us know if this works.
> 
> Thanks,
> -d


PS : 
(*)
 >limit
cputime      unlimited
filesize     unlimited
datasize     unlimited
stacksize    10240 kbytes
coredumpsize unlimited
memoryuse    unlimited
vmemoryuse   unlimited
descriptors  1024 
memorylocked 32 kbytes
maxproc      409600 

 >sysctl -A | egrep "shm"
vm.hugetlb_shm_group = 0
kernel.shmmni = 4096
kernel.shmall = 2097152
kernel.shmmax = 33554432

---------------
Bernard CHAMBON
IN2P3 / CNRS
04 72 69 42 18

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