new programs and exercises

C/Advanced/Parallel/MPI/Praticas/mpi_bug5.c

@@ -44,7 +44,10 @@ int main(int argc, char *argv[]) {
 }
 
 /*
-  PROBLEMA: Tipos?
+  PROBLEMA: Quando faz send, o processo 1 ao recever, os valores recevidos sao todos 0 (zeros)
+  HIPOTSE1: Deslocaçao mal formatada!
+  DUVIDA: O que faz a funçao Type_indexed??
+  
   CORREÇAO: ???
 
 

C/Advanced/Parallel/MPI/Praticas/mpi_bug7.c

@@ -0,0 +1,47 @@
+#include <mpi.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define REQS 1000
+#define DISP 100
+
+int main(int argc, char *argv[]) {
+  int numprocs, rank, tag, src, dest, num, offset, i;
+  MPI_Request reqs[REQS];
+
+  MPI_Init(&argc, &argv);
+  MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
+  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+ if (numprocs != 2) {
+    MPI_Finalize();
+    if (rank == 0)
+      printf("Run the program with 2 processes!\n");
+    exit(0);
+  }
+
+  printf("Proc %d starting...\n", rank);
+  MPI_Barrier(MPI_COMM_WORLD);
+  tag = 0;
+  if (rank == 0) {
+    dest = 1;
+    num = 1;
+    for (i = 1; i <= REQS; i++) {
+      MPI_Send(&num, 1, MPI_INT, dest, tag, MPI_COMM_WORLD);
+      if (i % DISP == 0)
+	printf("Proc %d has done %d sends\n", rank, i);
+    }
+  } else {
+    src = 0;
+    offset = 0;
+    for (i = 1; i <= REQS; i++) {
+      MPI_Irecv(&num, 1, MPI_INT, src, tag, MPI_COMM_WORLD, &reqs[offset]);
+      offset += 1;
+      if (i % DISP == 0)
+	printf("Proc %d has done %d irecvs\n", rank, i);
+    }
+  } 
+  MPI_Waitall(REQS, reqs, MPI_STATUS_IGNORE);
+
+  MPI_Finalize();
+}

C/Advanced/Parallel/MPI/Praticas/mpi_bug8.c

@@ -0,0 +1,88 @@
+#include <mpi.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define ARRAYSIZE 160
+#define MASTER	  0
+
+float data[ARRAYSIZE];
+float do_work(int rank, int offset, int chunksize);
+
+int main(int argc, char *argv[]) {
+  int numprocs, rank, tag1, tag2, src, dest, offset, chunksize, i, j;
+  float mysum, sum;
+
+  MPI_Init(&argc, &argv);
+  MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
+  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+  if (numprocs % 4 != 0) {
+    MPI_Finalize();
+    if (rank == 0)
+      printf("Number of procs must be divisible by 4!\n");
+    exit(0);
+  }
+
+  printf("Proc %d starting...\n", rank);
+  MPI_Barrier(MPI_COMM_WORLD);
+  chunksize = (ARRAYSIZE / numprocs);
+  tag1 = 1;
+  tag2 = 2;  
+  if (rank == MASTER) {
+    sum = 0;
+    for (i = 0; i < ARRAYSIZE; i++) {
+      data[i] = i * 1.0;
+      sum = sum + data[i];
+    }
+    printf("Initial sum = %f\n", sum);
+    offset = chunksize;
+    for (dest = 1; dest < numprocs; dest++) {
+      MPI_Send(&offset, 1, MPI_INT, dest, tag1, MPI_COMM_WORLD);
+      MPI_Send(&data[offset], chunksize, MPI_FLOAT, dest, tag2, MPI_COMM_WORLD);
+      printf("Sent %d elements to proc %d offset %d\n", chunksize, dest, offset);
+      offset = offset + chunksize;
+    }
+    offset = 0;
+    mysum = do_work(rank, offset, chunksize);
+    sum = mysum;
+    for (src = 1; src < numprocs; src++) {
+      MPI_Recv(&offset, 1, MPI_INT, src, tag1, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
+      MPI_Recv(&data[offset], chunksize, MPI_FLOAT, src, tag2, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
+      MPI_Recv(&mysum, 1, MPI_FLOAT, src, tag2, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
+      sum += mysum;
+    }
+    printf("Final sum = %f\n", sum);
+    printf("\nFinal results\n");
+    offset = 0;
+    for (i = 0; i < numprocs; i++) {
+      for (j = 0; j < chunksize; j++) 
+	printf("%f ", data[offset + j]);
+      offset = offset + chunksize;
+    }
+    printf("\n");
+  } else {
+    MPI_Recv(&offset, 1, MPI_INT, MASTER, tag1, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
+    MPI_Recv(&data[offset], chunksize, MPI_FLOAT, MASTER, tag2, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
+    mysum = do_work(rank, offset, chunksize);
+    MPI_Send(&offset, 1, MPI_INT, MASTER, tag1, MPI_COMM_WORLD);
+    MPI_Send(&data[offset], chunksize, MPI_FLOAT, MASTER, tag2, MPI_COMM_WORLD); 
+    MPI_Reduce(&mysum, &sum, 1, MPI_FLOAT, MPI_SUM, MASTER, MPI_COMM_WORLD);
+  }
+
+  MPI_Finalize(); 
+}
+
+
+float do_work(int rank, int offset, int chunksize) {
+  float sum;
+  int i; 
+
+  sum = 0;
+  for (i = offset; i < offset + chunksize; i++) {
+    data[i] = data[i] * 2;
+    sum = sum + data[i];
+  }
+  printf("Proc %d partial sum = %f\n", rank, sum);
+  return sum;
+}
+