Changes between Version 9 and Version 10 of YM_Course_2009/Lab8

Timestamp:

Jul 5, 2009, 3:31:27 PM (15 years ago)

Author:

jazz

Comment:

--

YM_Course_2009/Lab8

@@ -109 +109 @@
  * 用 mpicc 編譯 test1.c
 {{{
-ym000@bio001:~$ mpicc -o test1 test1.c
+ym24@bio001:~$ mpicc -o test1 test1.c
 }}}
  * 用 mpiexec 執行 test1 程式
 {{{
-ym000@bio001:~$ mpiexec -n 1 ./test1
+ym24@bio001:~$ mpiexec -n 1 ./test1
 This is machine 0 of 1 name = bio001
-ym000@bio001:~$ mpiexec -n 12 ./test1
-}}}
+ym24@bio001:~$ mpiexec -n 12 ./test1
+}}}
+ * here is test2.c
+{{{
+ym24@bio001:~$ cat << EOF > test2.c
+#include <mpi.h>
+#include <stdio.h>
+main(int argc,char **argv) { 
+  int n, myrank, numprocs;
+  MPI_Status status;
+  MPI_Init(&argc,&argv);
+  MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
+  MPI_Comm_rank(MPI_COMM_WORLD,&myrank);
+
+  /* node 0 will send the first message */
+  if(myrank == 0) {
+    n = myrank;
+    MPI_Send(&n, 1, MPI_INT, 1, 99, MPI_COMM_WORLD);
+    printf("[Ndde %d]「%d」 >> [Node %d]\n\n", myrank, n, myrank+1);
+  }
+
+  /* node 1 to node n-2 will send message to the next node */
+  if(myrank>0 && myrank<numprocs-1) {
+    MPI_Recv(&n, 1, MPI_INT, myrank-1, 99, MPI_COMM_WORLD, &status);
+    printf("[Node %d] << 「%d」[Node %d]\n", myrank, n, status.MPI_SOURCE);
+    n = myrank; MPI_Send(&n, 1, MPI_INT, myrank+1, 99, MPI_COMM_WORLD);
+    printf("[Ndde %d]「%d」 >> [Node %d]\n\n", myrank, n, myrank+1);
+  }
+
+ /* the final node n-1 will not send any message but receive*/
+  if(myrank==numprocs-1) {
+    MPI_Recv(&n, 1, MPI_INT, myrank-1, 99, MPI_COMM_WORLD, &status);
+    printf("[Node %d] << 「%d」[Node %d]\n", myrank, n, status.MPI_SOURCE);
+    }
+
+  MPI_Finalize();
+} 
+EOF
+}}}
+ * 用 mpicc 編譯 test2.c
+{{{
+ym24@bio001:~$ mpicc -o test2 test2.c
+}}}
+ * 用 mpiexec 執行 test2 程式
+{{{
+ym24@bio001:~$ mpiexec -n 12 ./test2
+}}}
+ * here is test3.c
+{{{
+ym24@bio001:~$ cat << EOF > test3.c
+/* Program:
+ *   每個 node 將訊息傳送給 node 0，由，node 0 統一印出
+ * History:
+ *   2008-06-12 BETA
+ *   2008-06-17 更改顯示方式，並增加註解
+ */
+
+#include <stdio.h>
+#include <mpi.h>
+#include <string.h>
+
+main(int argc, char **argv)
+{
+  int myrank, i, numprocs;
+  char message[20];
+  MPI_Status status;
+  MPI_Init(&argc, &argv);
+  MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
+  MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
+
+  /* Node 0 will do the following */
+  if(myrank == 0)
+  {
+    /* receive messages from other nodes */
+    for(i = 1; i < numprocs; i++)
+    {
+      MPI_Recv(message, 20, MPI_CHAR, i, 99, MPI_COMM_WORLD, &status);
+      printf("[Node 0] << 「%s」[Node %d] \n", message, status.MPI_SOURCE);
+    }
+  }
+
+  /* other Nodes will do the following */
+  if(myrank != 0)
+  {
+    /* send node's rank to Node 0 */
+    sprintf(message, "[%d]", myrank);
+    MPI_Send(message, 20, MPI_CHAR, 0, 99, MPI_COMM_WORLD);
+    printf("[Node %d]「%s」 >> [Node 0]\n", myrank, message);
+  }
+  MPI_Finalize();
+}
+EOF
+}}}
+ * 用 mpicc 編譯 test3.c
+{{{
+ym24@bio001:~$ mpicc -o test2 test3.c
+}}}
+ * 用 mpiexec 執行 test3 程式
+{{{
+ym24@bio001:~$ mpiexec -n 12 ./test3
+}}}
+ * here is test4
+{{{
+ym24@bio001:~$ cat << EOF > test4.c
+/* Program:
+ *   mpich_example 內建範例，計算 pi 。
+ * History:
+ *   2008-04-11 BETA
+ *   2008-06-19 增加可重複輸入欲計算之精準度
+ *   2008-06-23 加入 MPI_Barrier 以確保每個 node 在接受 n 後才執行
+ */
+
+#include "mpi.h"
+#include <stdio.h>
+#include <math.h>
+#include <time.h>
+
+double f( double );
+double f( double a )
+{
+    return (4.0 / (1.0 + a*a));
+}
+
+int main( int argc, char *argv[])
+{
+    int done = 0, n, myid, numprocs, i=0;
+    double PI25DT = 3.141592653589793238462643;
+    double mypi, pi, h, sum, x;
+    double startwtime = 0.0, endwtime;
+    int  namelen;
+    char processor_name[MPI_MAX_PROCESSOR_NAME];
+    MPI_Init(&argc,&argv);
+    MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
+    MPI_Comm_rank(MPI_COMM_WORLD,&myid);
+    MPI_Get_processor_name(processor_name,&namelen);
+    fprintf(stderr,"Process %d on %s\n",
+            myid, processor_name);
+    n = 0;
+    while (!done)
+    {
+        /* 由 node 0 將使用者輸入的值送給其它的 node  */
+        if (myid == 0)
+        {
+            printf("Enter the number of intervals: (0 quits) ");
+            scanf("%d", &n);
+            startwtime = MPI_Wtime();
+        }
+
+        /* 這非常重要，所有的 node 必需在此同步，才可以收到使用者輸入的 n */
+        MPI_Barrier(MPI_COMM_WORLD);
+
+        /* 將 n 送給其它的 node  */
+        MPI_Bcast(&n, 1, MPI_INT, 0, MPI_COMM_WORLD);
+        if (n == 0)
+            done = 1;
+        else
+        {
+
+            /* 此為計算 pi 的演算法 */
+            h   = 1.0 / (double) n;
+            sum = 0.0;
+            for (i = myid + 1; i <= n; i += numprocs)
+            {
+                x = h * ((double)i - 0.5);
+                sum += f(x);
+            }
+            mypi = h * sum;
+
+            /* 將算完的結果傳給 node 0 加總 */
+            MPI_Reduce(&mypi, &pi, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
+            if (myid == 0)
+            {
+                printf("pi is approximately %.16f, Error is %.16f\n",
+                       pi, fabs(pi - PI25DT));
+                endwtime = MPI_Wtime();
+                printf("wall clock time = %f\n",
+                       endwtime-startwtime);
+            }
+        }
+    }
+    MPI_Finalize();
+    return 0;
+}
+EOF
+}}}
+ * 用 mpicc 編譯 test4.c
+{{{
+ym24@bio001:~$ mpicc -o test2 test4.c
+}}}
+ * 用 mpiexec 執行 test4 程式
+{{{
+ym24@bio001:~$ mpiexec -n 12 ./test4
+}}}