diff --git a/src/examples/matmult.c b/src/examples/matmult.c new file mode 100644 index 0000000000000000000000000000000000000000..f7ed4dee010ea163e9e25fb094e380ddece16e8f --- /dev/null +++ b/src/examples/matmult.c @@ -0,0 +1,57 @@ +/* matmult.c + + Test program to do matrix multiplication on large arrays. + + Intended to stress virtual memory system. + + Ideally, we could read the matrices off of the file system, + and store the result back to the file system! + */ + +#include <stdio.h> +#include <syscall.h> + +/* You should define DIM to be large enough that the arrays + don't fit in physical memory. + + Dim Memory + ------ -------- + 16 3 kB + 64 48 kB + 128 192 kB + 256 768 kB + 512 3,072 kB + 1,024 12,288 kB + 2,048 49,152 kB + 4,096 196,608 kB + 8,192 786,432 kB + 16,384 3,145,728 kB */ +#define DIM 128 + +int A[DIM][DIM]; +int B[DIM][DIM]; +int C[DIM][DIM]; + +int +main (void) +{ + int i, j, k; + + /* Initialize the matrices. */ + for (i = 0; i < DIM; i++) + for (j = 0; j < DIM; j++) + { + A[i][j] = i; + B[i][j] = j; + C[i][j] = 0; + } + + /* Multiply matrices. */ + for (i = 0; i < DIM; i++) + for (j = 0; j < DIM; j++) + for (k = 0; k < DIM; k++) + C[i][j] += A[i][k] * B[k][j]; + + /* Done. */ + exit (C[DIM - 1][DIM - 1]); +}