Messages in this thread |  | | Date | Tue, 09 Oct 2001 16:31:47 +0200 | From | Lorenzo Allegrucci <> | Subject | qsbench |
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I've rewritten the "qsort test" again, now it uses its own qsort and it's much faster than the previous qs.c. Renamed qs.c to qsbench.c :) Previous results are not comparable. Three sequential runs of qsbench with the same seed = 140175100
Results below, qsbench.c code to the end.
Linux-2.4.11-pre5:
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 70.950u 1.890s 2:20.41 51.8% 0+0k 0+0io 10671pf+0w
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 71.370u 1.610s 2:20.85 51.8% 0+0k 0+0io 10591pf+0w
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 70.870u 1.700s 2:20.99 51.4% 0+0k 0+0io 10587pf+0w
Linux-2.4.10-ac9:
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 70.940u 2.420s 3:21.21 36.4% 0+0k 0+0io 12745pf+0w
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 72.240u 3.250s 4:01.99 31.1% 0+0k 0+0io 15616pf+0w
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 71.530u 2.560s 3:33.09 34.7% 0+0k 0+0io 13095pf+0w
Linux-2.4.10-ac9 + Rik's eatcache patch:
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 71.680u 2.410s 3:30.48 35.2% 0+0k 0+0io 12603pf+0w
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 72.070u 2.460s 3:53.87 31.8% 0+0k 0+0io 15361pf+0w
time ./qsbench -n 90000000 -p 1 -s 140175100 seed = 140175100 71.240u 2.940s 4:36.24 26.8% 0+0k 0+0io 17801pf+0w
I would say qsbench can't give a definitive answer on this patch because results are not enough reproducible. Maybe qsbench is not even suited to test this patch, I suspect. Anyway, here's the qsbench.c new code,
/* * Copyright (C) 2001 Lorenzo Allegrucci (lenstra@tiscalinet.it) * Licensed under the GPL */ #include <stdio.h> #include <stdlib.h> #include <malloc.h> #include <unistd.h> #include <sys/types.h> #include <sys/wait.h>
#define MAX_PROCS 1024
/** * quick_sort - Sort in the range [l, r] */ void quick_sort(int a[], int l, int r) { int i, j, p, tmp; int m, min, max;
i = l; j = r; m = (l + r) >> 1;
if (a[m] >= a[l]) { max = a[m]; min = a[l]; } else { max = a[l]; min = a[m]; }
if (a[r] >= max) p = max; else { if (a[r] >= min) p = a[r]; else p = min; }
do { while (a[i] < p) i++;
while (p < a[j]) j--;
if (i <= j) { tmp = a[i]; a[i] = a[j]; a[j] = tmp; i++; j--; } } while (i <= j);
if (l < j) quick_sort(a, l, j);
if (i < r) quick_sort(a, i, r); }
void do_qsort(int n, int s) { int * a, i, errors = 0;
if ((a = malloc(sizeof(int) * n)) == NULL) { perror("malloc"); exit(1); }
srand(s); printf("seed = %d\n", s);
for (i = 0; i < n; i++) a[i] = rand();
quick_sort(a, 0, n - 1);
for (i = 0; i < n - 1; i++) if (a[i] > a[i + 1]) errors++; if (errors) fprintf(stderr, "WARNING: %d errors.\n", errors); free(a); exit(0); }
void start_procs(int n, int p, int s) { int i, pid[MAX_PROCS]; int status;
if (p > MAX_PROCS) p = MAX_PROCS;
for (i = 0; i < p; i++) { pid[i] = fork(); if (pid[i] == 0) do_qsort(n, s); else if (pid[i] < 0) perror("fork"); }
for (i = 0; i < p; i++) waitpid(pid[i], &status, 0); }
void usage(void) { fprintf(stderr, "Usage: qs [-h] [-n nr_elems] [-p nr_procs]" " [-s seed]\n"); exit(1); }
int main(int argc, char * argv[]) { char * n = NULL, * p = NULL, * s = NULL; int nr_elems = 1000000, nr_procs = 1, seed = 1; int c;
if (argc == 1) usage();
while (1) { c = getopt(argc, argv, "hn:p:s:V"); if (c == -1) break;
switch (c) { case 'h': usage(); case 'n': n = optarg; nr_elems = atoi(n); break; case 'p': p = optarg; nr_procs = atoi(p); break; case 's': s = optarg; seed = atoi(s); break; case 'V': printf("Version 0.92\n"); return 1; case '?': return 1; } }
start_procs(nr_elems, nr_procs, seed);
return 0; }
-- Lorenzo
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