openmpi

问题 Do we have any limits about message size on MPI_Send or MPI_Recv - or limits by computer? When I try to send large data, it can not completed. This is my code: #include <stdio.h> #include <stdlib.h> #include <mpi.h> #include <math.h> #include <string.h> void AllGather_ring(void* data, int count, MPI_Datatype datatype,MPI_Comm communicator) { int me; MPI_Comm_rank(communicator, &me); int world_size; MPI_Comm_size(communicator, &world_size); int next=me+1; if(next>=world_size) next=0; int prev

问题 Backgroup: rank 0 send message to rank 1, after rank 1 completes its work it returns messages to rank 0 actually I run a thread for sending message and the other one for receiving in rank 0 like this: int tag = 1; void* thread_send(void* argc) { ...; while(1) { if(tag == 1) { MPI_Send(...,1,TAG_SEND,...);//send something to slave tag = 0; } } ... } void* thread_receive(void* argc) { while(1) { MPI_Recv(...,0,TAG_RECV,...); //ready for receiving from slave tag = 1; } } in rank 1 I run a thread

问题 I have successfully set up the password less ssh between the servers and my computer. There is a simple openMPI program which is running well on the single computer. But ,unfortunately when i am trying this on a cluster ,neither i am getting a password prompt(as i have set up ssh authorization) nor the execution is moving forward. Hostfile looks like this, # The Hostfile for Open MPI # The master node, 'slots=8' is used because it has 8 cores localhost slots=8 # The following slave nodes are

问题 My basic question is about how the suppression files work in valgrind. I have looked at a lot of the documentation that points to using the following on mpi versions > 1.5 (mine is 1.6): mpirun -np 2 valgrind --suppressions=/usr/share/openmpi/openmpi-valgrind.supp --track-origins=yes ./myprog However, when I run it like this the file has over 600 errors! The errors I am getting are these two over and over. I don't know how to interpret either one of these with my current understanding of

问题 Using g++ version 4.9 in Ubuntu, when compiling a C++ source file named test.cpp that needs a shared library named libUtils.so (which in its turn needs Open MPI shared library, hence the parameter -Wl,-rpath-link,/home/dummy/openmpi/build/lib ) as follows: g++ test.cpp -lUtils -Wl,-rpath-link,/home/dummy/openmpi/build/lib An error is thrown /home/dummy/openmpi/build/lib/libopen-pal.so.20: undefined reference to pthread_atfork . I passed -pthread and -lpthread to g++ but none of these solved

问题 I'm trying to spread data across multiple workers using OpenMPI, however, I'm doing the data division in a fairly custom way that is not amenable to MPI_Scatter or MPI_Broadcast . What I would like to do is to give each processor some work in a queue (or, some other async mechanism) such that they can do their work on the first chunk of data, take the next chunk, repeat until no more chunks. I know of MPI_Isend , however if I send data with MPI_Isend I can't modify it until it's finished

问题 I am trying to run the following MPI code. The problem is with the scanf . The command keep on taking input and does not anywhere. It is supposed to take one input string only. #include <stdio.h> #include <stdlib.h> #include <string.h> #include <mpi.h> int main(int argc,char * argv[]) { int npes, myrank, length = 10; char string[length+1]; // array size changed to length +1 as suggested in comments. memset(string, 0, length+1); MPI_Init(&argc, &argv); MPI_Comm_size(MPI_COMM_WORLD, &npes); MPI

问题 When trying to install OpenMPI the .configure filed failed in the section checking for ISO C99 ability of the selected compiler. Puzzled as gcc of course has both the std=gnu99 and std=c99 option, I pruning the 20,000 lines configure file to isolate the offending section. In the end I traced it back to gcc 5 not compiling variable argument functions. The below code generates the "suffix or operands invalid for `movq'" error, which is the root cause of the .configure file failing. (The step-by

问题 I just use a valgrind to test an example provide in openmpi-1.4/example: mpirun.openmpi --np 2 valgrind --log-file=output.dat --leak-check=full --tool=memcheck ./ring_c then I found below in output.dat: ==30450== Syscall param writev(vector[...]) points to uninitialised byte(s) ==30450== at 0x54DC150: __writev_nocancel (syscall-template.S:81) ==30450== by 0x7E3B312: mca_oob_tcp_msg_send_handler (in /usr/lib/openmpi/lib/openmpi/mca_oob_tcp.so) ==30450== by 0x7E3C50A: mca_oob_tcp_peer_send (in

问题 I have an R package that sends out a job to the OpenMPI cluster I have running by means of the Rmpi package. All works as expected within an R session run from the console. However, when I try to execute the relevant function with from my OpenCPU server like this (details changed to protect the innocent): curl -XPOST http://99.999.999.99/ocpu/library/MyPackage/R/my_cluster_function I get this error: R call failed: process died. (Other, non-cluster calling functions within the package work as