MPI_Scatter 2d向量 [英] MPI_Scatter 2d vector
本文介绍了MPI_Scatter 2d向量的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我需要将vector的片段传递给所有进程，以对matrix进行乘法运算.我想传递一个向量(orginal_size/processes)的向量.
std::vector<double> Algorytm::mnozenie(std::vector< std::vector <double> > matrix,std::vector<double> wektor){
std::vector<double> wynik(matrix.size(),0);
if (rozmiar_macierzy_==(int)wektor.size()){
int size=matrix.size();
int world_size;
MPI_Comm_size(MPI_COMM_WORLD, &world_size);
MPI_Bcast(&size,1 , MPI_INT,0,MPI_COMM_WORLD);
MPI_Bcast(&wektor.front(),wektor.size() , MPI_DOUBLE,0,MPI_COMM_WORLD);
std::vector< std::vector <double> > fragment_of_matrix(matrix.size()/world_size);
std::vector <double> tmp(size);
for(int i=0;i<fragment_of_matrix.size();i++){
fragment_of_matrix.at(i)=tmp;
}
int small_size=matrix.size()*matrix.at(0).size()/world_size;
std::vector<double> wektor2(wektor.size()/world_size);
// This works
MPI_Scatter(&wektor.front(),wektor.size()/world_size , MPI_DOUBLE,&wektor2.front(),wektor.size()/world_size , MPI_DOUBLE, 0,MPI_COMM_WORLD);
//This doesn't :(
MPI_Scatter(&matrix.front(),small_size, MPI_DOUBLE,&fragment_of_matrix.front(), small_size, MPI_DOUBLE, 0,MPI_COMM_WORLD);
}
else{
std::cout << "[ERROR]:"<<std::endl;
}
return wynik;
}
MPI_Scatter(&matrix.front() ...导致错误:
orrMPI(38789,0x7fff76af2000) malloc: *** error for object 0x3ff0000000000000: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
[MBP-2:38789] *** Process received signal ***
[MBP-2:38789] Signal: Abort trap: 6 (6)
[MBP-2:38789] Signal code: (0)
[MBP-2:38789] [ 0] porrMPI(38788,0x7fff76af2000) malloc: *** error for object 0x7f8b618da200: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
fragment_macierzy rozmiar: 75x150 0 libsystem_platform.dylib 0x00007fff8c29feaa _sigtramp + 26
[MBP-2:38789] [ 1] 0 ??? 0x0000000000000000 0x0 + 0
[MBP-2:38789] [ 2] 0 libsystem_c.dylib 0x00007fff975696e7 abort + 129
[MBP-2:38789] [ 3] 0 libsystem_malloc.dylib 0x00007fff8e66c070 free + 425
[MBP-2:38789] [ 4] 0 porrMPI 0x0000000101e77bed _ZNSt3__113__vector_baseIdNS_9allocatorIdEEED2Ev + 509
[MBP-2:38789] [ 5] 0 porrMPI 0x0000000101e779e5 _ZNSt3__16vectorIdNS_9allocatorIdEEED2Ev + 21
[MBP-2:38789] [ 6] 0 porrMPI 0x0000000101e727b5 _ZNSt3__16vectorIdNS_9allocatorIdEEED1Ev + 21
[MBP-2:38789] [ 7] 0 porrMPI 0x0000000101e77d33 _ZNSt3__113__vector_baseINS_6vectorIdNS_9allocatorIdEEEENS2_IS4_EEED2Ev + 275
[MBP-2:38789] [ 8] 0 porrMPI 0x0000000101e77c15 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED2Ev + 21
[MBP-2:38789] [ 9] 0 porrMPI 0x0000000101e727f5 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED1Ev + 21
[MBP-2:38788] *** Process received signal ***
[MBP-2:38788] Signal: Abort trap: 6 (6)
[MBP-2:38788] Signal code: (0)
[MBP-2:38788] [ 0] 0 libsystem_platform.dylib 0x00007fff8c29feaa _sigtramp + 26
[MBP-2:38788] [ 1] 0 ??? 0x0000ffff00001fa0 0x0 + 281470681751456
[MBP-2:38788] [ 2] 0 libsystem_c.dylib 0x00007fff975696e7 abort + 129
[MBP-2:38788] [ 3] 0 libsystem_malloc.dylib 0x00007fff8e66c070 free + 425
[MBP-2:38788] [ 4] 0 porrMPI 0x000000010b4cdbed _ZNSt3__113__vector_baseIdNS_9allocatorIdEEED2Ev + 509
[MBP-2:38788] [ 5] 0 porrMPI 0x000000010b4cd9e5 _ZNSt3__16vectorIdNS_9allocatorIdEEED2Ev + 21
[MBP-2:38788] [ 6] 0 porrMPI 0x000000010b4c87b5 _ZNSt3__16vectorIdNS_9allocatorIdEEED1Ev + 21
[MBP-2:38788] [ 7] 0 porrMPI 0x000000010b4cdd33 _ZNSt3__113__vector_baseINS_6vectorIdNS_9allocatorIdEEEENS2_IS4_EEED2Ev + 275
[MBP-2:38788] [ 8] 0 porrMPI 0x000000010b4cdc15 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED2Ev + 21
[MBP-2:38788] [ 9] 0 porrMPI 0x000000010b4c87f5 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED1Ev + 21
[MBP-2:38788] [10] 0 porrMPI 0x000000010b4d48d1 _ZN17AlgorytmCzebyszew19obliczMacierzRownanEv + 8289
[MBP-2:38788] [11] 0 porrMPI 0x000000010b4d7f78 main + 504
[MBP-2:38788] [12] 0 libdyld.dylib 0x00007fff976475ad start + 1
[MBP-2:38788] [13] 0 ??? 0x0000000000000001 0x0 + 1
[MBP-2:38788] *** End of error message ***
[MBP-2:38789] [10] 0 porrMPI 0x0000000101e8235c _Z5slavev + 700
[MBP-2:38789] [11] 0 porrMPI 0x0000000101e81e54 main + 212
[MBP-2:38789] [12] 0 libdyld.dylib 0x00007fff976475ad start + 1
[MBP-2:38789] [13] 0 ??? 0x0000000000000001 0x0 + 1
[MBP-2:38789] *** End of error message ***
--------------------------------------------------------------------------
mpiexec noticed that process rank 0 with PID 38788 on node MBP-2 exited on signal 6 (Abort trap: 6).
如何正确地将此2d向量的块传递给所有进程?
解决方案
2D向量不连续.因此，在计算 small_size 时，您可能会获得向量的确切大小，但是地址在内存中并不连续.因此，当您尝试尝试 MPI_Scatter 时，可能会对不可用的地址执行分散操作.
解决此问题的唯一选项；
- 从2维矢量矩阵创建一维矢量作为temp_matrix.然后，对temp_matrix执行分散操作.确保接收器还具有一维temp_matrix.这种解决方案几乎就像将二维向量转换为数组并执行散点运算，然后再从数组移回向量.
但是，如果向量的大小将很大，这将是最愚蠢的解决方案.我希望这对您来说不是问题，因为如果一个PE(这里是主PE 0)可以容纳完整的 matrix 向量，那么大小就不会那么大.
I need to pass fragments of vector to all processes to make multiplication operation on matrix . I want to pass a vector (of orginal_size/processes) of vectors.
std::vector<double> Algorytm::mnozenie(std::vector< std::vector <double> > matrix,std::vector<double> wektor){
std::vector<double> wynik(matrix.size(),0);
if (rozmiar_macierzy_==(int)wektor.size()){
int size=matrix.size();
int world_size;
MPI_Comm_size(MPI_COMM_WORLD, &world_size);
MPI_Bcast(&size,1 , MPI_INT,0,MPI_COMM_WORLD);
MPI_Bcast(&wektor.front(),wektor.size() , MPI_DOUBLE,0,MPI_COMM_WORLD);
std::vector< std::vector <double> > fragment_of_matrix(matrix.size()/world_size);
std::vector <double> tmp(size);
for(int i=0;i<fragment_of_matrix.size();i++){
fragment_of_matrix.at(i)=tmp;
}
int small_size=matrix.size()*matrix.at(0).size()/world_size;
std::vector<double> wektor2(wektor.size()/world_size);
// This works
MPI_Scatter(&wektor.front(),wektor.size()/world_size , MPI_DOUBLE,&wektor2.front(),wektor.size()/world_size , MPI_DOUBLE, 0,MPI_COMM_WORLD);
//This doesn't :(
MPI_Scatter(&matrix.front(),small_size, MPI_DOUBLE,&fragment_of_matrix.front(), small_size, MPI_DOUBLE, 0,MPI_COMM_WORLD);
}
else{
std::cout << "[ERROR]:"<<std::endl;
}
return wynik;
}
MPI_Scatter(&matrix.front() ... causes error:
orrMPI(38789,0x7fff76af2000) malloc: *** error for object 0x3ff0000000000000: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
[MBP-2:38789] *** Process received signal ***
[MBP-2:38789] Signal: Abort trap: 6 (6)
[MBP-2:38789] Signal code: (0)
[MBP-2:38789] [ 0] porrMPI(38788,0x7fff76af2000) malloc: *** error for object 0x7f8b618da200: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
fragment_macierzy rozmiar: 75x150 0 libsystem_platform.dylib 0x00007fff8c29feaa _sigtramp + 26
[MBP-2:38789] [ 1] 0 ??? 0x0000000000000000 0x0 + 0
[MBP-2:38789] [ 2] 0 libsystem_c.dylib 0x00007fff975696e7 abort + 129
[MBP-2:38789] [ 3] 0 libsystem_malloc.dylib 0x00007fff8e66c070 free + 425
[MBP-2:38789] [ 4] 0 porrMPI 0x0000000101e77bed _ZNSt3__113__vector_baseIdNS_9allocatorIdEEED2Ev + 509
[MBP-2:38789] [ 5] 0 porrMPI 0x0000000101e779e5 _ZNSt3__16vectorIdNS_9allocatorIdEEED2Ev + 21
[MBP-2:38789] [ 6] 0 porrMPI 0x0000000101e727b5 _ZNSt3__16vectorIdNS_9allocatorIdEEED1Ev + 21
[MBP-2:38789] [ 7] 0 porrMPI 0x0000000101e77d33 _ZNSt3__113__vector_baseINS_6vectorIdNS_9allocatorIdEEEENS2_IS4_EEED2Ev + 275
[MBP-2:38789] [ 8] 0 porrMPI 0x0000000101e77c15 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED2Ev + 21
[MBP-2:38789] [ 9] 0 porrMPI 0x0000000101e727f5 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED1Ev + 21
[MBP-2:38788] *** Process received signal ***
[MBP-2:38788] Signal: Abort trap: 6 (6)
[MBP-2:38788] Signal code: (0)
[MBP-2:38788] [ 0] 0 libsystem_platform.dylib 0x00007fff8c29feaa _sigtramp + 26
[MBP-2:38788] [ 1] 0 ??? 0x0000ffff00001fa0 0x0 + 281470681751456
[MBP-2:38788] [ 2] 0 libsystem_c.dylib 0x00007fff975696e7 abort + 129
[MBP-2:38788] [ 3] 0 libsystem_malloc.dylib 0x00007fff8e66c070 free + 425
[MBP-2:38788] [ 4] 0 porrMPI 0x000000010b4cdbed _ZNSt3__113__vector_baseIdNS_9allocatorIdEEED2Ev + 509
[MBP-2:38788] [ 5] 0 porrMPI 0x000000010b4cd9e5 _ZNSt3__16vectorIdNS_9allocatorIdEEED2Ev + 21
[MBP-2:38788] [ 6] 0 porrMPI 0x000000010b4c87b5 _ZNSt3__16vectorIdNS_9allocatorIdEEED1Ev + 21
[MBP-2:38788] [ 7] 0 porrMPI 0x000000010b4cdd33 _ZNSt3__113__vector_baseINS_6vectorIdNS_9allocatorIdEEEENS2_IS4_EEED2Ev + 275
[MBP-2:38788] [ 8] 0 porrMPI 0x000000010b4cdc15 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED2Ev + 21
[MBP-2:38788] [ 9] 0 porrMPI 0x000000010b4c87f5 _ZNSt3__16vectorINS0_IdNS_9allocatorIdEEEENS1_IS3_EEED1Ev + 21
[MBP-2:38788] [10] 0 porrMPI 0x000000010b4d48d1 _ZN17AlgorytmCzebyszew19obliczMacierzRownanEv + 8289
[MBP-2:38788] [11] 0 porrMPI 0x000000010b4d7f78 main + 504
[MBP-2:38788] [12] 0 libdyld.dylib 0x00007fff976475ad start + 1
[MBP-2:38788] [13] 0 ??? 0x0000000000000001 0x0 + 1
[MBP-2:38788] *** End of error message ***
[MBP-2:38789] [10] 0 porrMPI 0x0000000101e8235c _Z5slavev + 700
[MBP-2:38789] [11] 0 porrMPI 0x0000000101e81e54 main + 212
[MBP-2:38789] [12] 0 libdyld.dylib 0x00007fff976475ad start + 1
[MBP-2:38789] [13] 0 ??? 0x0000000000000001 0x0 + 1
[MBP-2:38789] *** End of error message ***
--------------------------------------------------------------------------
mpiexec noticed that process rank 0 with PID 38788 on node MBP-2 exited on signal 6 (Abort trap: 6).
how to correctly pass chunks of this 2d vector to all processes?
解决方案
2D vectors are not contiguous. Hence, while calculating small_size you might get the exact size of the vector, but the address is not contiguous in the memory. So, when you try attempting MPI_Scatter, the scatter operation might be performed on an unavailable address.
The only option to fix this;
- create a single dimensional vector as temp_matrix from the 2-d vector matrix. And, then perform a scatter operation on the temp_matrix. Make sure the receiver also has a 1-d temp_matrix. This solution is almost like converting a 2-d vector into an array and performing scatter operation, before moving back to vector from the array.
But, this would be the most silly solution if the size of the vector is going to be huge. I hope this shouldn't be an issue in your case, because if one PE(here the master PE 0) can hold the complete matrix vector, then the size shouldn't be that huge.
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