On 7/15/2010 10:18 AM, Eloi Gaudry wrote: > hi edgar, > > thanks for the tips, I'm gonna try this option as well. the segmentation > fault i'm observing always happened during a collective communication > indeed... > does it basically switch all collective communication to basic mode, right ? > > sorry for my ignorance, but what's a NCA ?
sorry, I meant to type HCA (InifinBand networking card) Thanks Edgar > > thanks, > éloi > > On Thursday 15 July 2010 16:20:54 Edgar Gabriel wrote: >> you could try first to use the algorithms in the basic module, e.g. >> >> mpirun -np x --mca coll basic ./mytest >> >> and see whether this makes a difference. I used to observe sometimes a >> (similar ?) problem in the openib btl triggered from the tuned >> collective component, in cases where the ofed libraries were installed >> but no NCA was found on a node. It used to work however with the basic >> component. >> >> Thanks >> Edgar >> >> On 7/15/2010 3:08 AM, Eloi Gaudry wrote: >>> hi Rolf, >>> >>> unfortunately, i couldn't get rid of that annoying segmentation fault >>> when selecting another bcast algorithm. i'm now going to replace >>> MPI_Bcast with a naive implementation (using MPI_Send and MPI_Recv) and >>> see if that helps. >>> >>> regards, >>> éloi >>> >>> On Wednesday 14 July 2010 10:59:53 Eloi Gaudry wrote: >>>> Hi Rolf, >>>> >>>> thanks for your input. You're right, I miss the >>>> coll_tuned_use_dynamic_rules option. >>>> >>>> I'll check if I the segmentation fault disappears when using the basic >>>> bcast linear algorithm using the proper command line you provided. >>>> >>>> Regards, >>>> Eloi >>>> >>>> On Tuesday 13 July 2010 20:39:59 Rolf vandeVaart wrote: >>>>> Hi Eloi: >>>>> To select the different bcast algorithms, you need to add an extra mca >>>>> parameter that tells the library to use dynamic selection. >>>>> --mca coll_tuned_use_dynamic_rules 1 >>>>> >>>>> One way to make sure you are typing this in correctly is to use it with >>>>> ompi_info. Do the following: >>>>> ompi_info -mca coll_tuned_use_dynamic_rules 1 --param coll >>>>> >>>>> You should see lots of output with all the different algorithms that >>>>> can be selected for the various collectives. >>>>> Therefore, you need this: >>>>> >>>>> --mca coll_tuned_use_dynamic_rules 1 --mca coll_tuned_bcast_algorithm 1 >>>>> >>>>> Rolf >>>>> >>>>> On 07/13/10 11:28, Eloi Gaudry wrote: >>>>>> Hi, >>>>>> >>>>>> I've found that "--mca coll_tuned_bcast_algorithm 1" allowed to switch >>>>>> to the basic linear algorithm. Anyway whatever the algorithm used, the >>>>>> segmentation fault remains. >>>>>> >>>>>> Does anyone could give some advice on ways to diagnose the issue I'm >>>>>> facing ? >>>>>> >>>>>> Regards, >>>>>> Eloi >>>>>> >>>>>> On Monday 12 July 2010 10:53:58 Eloi Gaudry wrote: >>>>>>> Hi, >>>>>>> >>>>>>> I'm focusing on the MPI_Bcast routine that seems to randomly segfault >>>>>>> when using the openib btl. I'd like to know if there is any way to >>>>>>> make OpenMPI switch to a different algorithm than the default one >>>>>>> being selected for MPI_Bcast. >>>>>>> >>>>>>> Thanks for your help, >>>>>>> Eloi >>>>>>> >>>>>>> On Friday 02 July 2010 11:06:52 Eloi Gaudry wrote: >>>>>>>> Hi, >>>>>>>> >>>>>>>> I'm observing a random segmentation fault during an internode >>>>>>>> parallel computation involving the openib btl and OpenMPI-1.4.2 (the >>>>>>>> same issue can be observed with OpenMPI-1.3.3). >>>>>>>> >>>>>>>> mpirun (Open MPI) 1.4.2 >>>>>>>> Report bugs to http://www.open-mpi.org/community/help/ >>>>>>>> [pbn08:02624] *** Process received signal *** >>>>>>>> [pbn08:02624] Signal: Segmentation fault (11) >>>>>>>> [pbn08:02624] Signal code: Address not mapped (1) >>>>>>>> [pbn08:02624] Failing at address: (nil) >>>>>>>> [pbn08:02624] [ 0] /lib64/libpthread.so.0 [0x349540e4c0] >>>>>>>> [pbn08:02624] *** End of error message *** >>>>>>>> sh: line 1: 2624 Segmentation fault >>>>>>>> >>>>>>>> \/share\/hpc3\/actran_suite\/Actran_11\.0\.rc2\.41872\/RedHatEL\-5\/ >>>>>>>> x 86 _6 4\ /bin\/actranpy_mp >>>>>>>> '--apl=/share/hpc3/actran_suite/Actran_11.0.rc2.41872/RedHatEL-5/x86 >>>>>>>> _ 64 /A c tran_11.0.rc2.41872' >>>>>>>> '--inputfile=/work/st25652/LSF_130073_0_47696_0/Case1_3Dreal_m4_n2.d >>>>>>>> a t' '--scratch=/scratch/st25652/LSF_130073_0_47696_0/scratch' >>>>>>>> '--mem=3200' '--threads=1' '--errorlevel=FATAL' '--t_max=0.1' >>>>>>>> '--parallel=domain' >>>>>>>> >>>>>>>> If I choose not to use the openib btl (by using --mca btl >>>>>>>> self,sm,tcp on the command line, for instance), I don't encounter >>>>>>>> any problem and the parallel computation runs flawlessly. >>>>>>>> >>>>>>>> I would like to get some help to be able: >>>>>>>> - to diagnose the issue I'm facing with the openib btl >>>>>>>> - understand why this issue is observed only when using the openib >>>>>>>> btl and not when using self,sm,tcp >>>>>>>> >>>>>>>> Any help would be very much appreciated. >>>>>>>> >>>>>>>> The outputs of ompi_info and the configure scripts of OpenMPI are >>>>>>>> enclosed to this email, and some information on the infiniband >>>>>>>> drivers as well. >>>>>>>> >>>>>>>> Here is the command line used when launching a parallel computation >>>>>>>> >>>>>>>> using infiniband: >>>>>>>> path_to_openmpi/bin/mpirun -np $NPROCESS --hostfile host.list >>>>>>>> --mca >>>>>>>> >>>>>>>> btl openib,sm,self,tcp --display-map --verbose --version --mca >>>>>>>> mpi_warn_on_fork 0 --mca btl_openib_want_fork_support 0 [...] >>>>>>>> >>>>>>>> and the command line used if not using infiniband: >>>>>>>> path_to_openmpi/bin/mpirun -np $NPROCESS --hostfile host.list >>>>>>>> --mca >>>>>>>> >>>>>>>> btl self,sm,tcp --display-map --verbose --version --mca >>>>>>>> mpi_warn_on_fork 0 --mca btl_openib_want_fork_support 0 [...] >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Eloi >>>>>> >>>>>> _______________________________________________ >>>>>> users mailing list >>>>>> us...@open-mpi.org >>>>>> http://www.open-mpi.org/mailman/listinfo.cgi/users >
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