/usr/src/openvswitch-1.4.0/tests/test-multipath.c is in openvswitch-datapath-dkms 1.4.0-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 | /*
* Copyright (c) 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "multipath.h"
#include <assert.h>
#include <getopt.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "flow.h"
#include "random.h"
#include "util.h"
int
main(int argc, char *argv[])
{
enum { MP_MAX_LINKS = 63 };
struct nx_action_multipath mp;
bool ok = true;
int n;
set_program_name(argv[0]);
random_init();
if (argc != 2) {
ovs_fatal(0, "usage: %s multipath_action", program_name);
}
multipath_parse(&mp, argv[1]);
for (n = 1; n <= MP_MAX_LINKS; n++) {
enum { N_FLOWS = 65536 };
double disruption, perfect, distribution;
int histogram[MP_MAX_LINKS];
double sum_dev2, stddev;
int changed;
int i;
changed = 0;
memset(histogram, 0, sizeof histogram);
for (i = 0; i < N_FLOWS; i++) {
int old_link, new_link;
struct flow flow;
random_bytes(&flow, sizeof flow);
mp.max_link = htons(n - 1);
multipath_execute(&mp, &flow);
old_link = flow.regs[0];
mp.max_link = htons(n);
multipath_execute(&mp, &flow);
new_link = flow.regs[0];
assert(old_link >= 0 && old_link < n);
assert(new_link >= 0 && new_link < n + 1);
histogram[old_link]++;
changed += old_link != new_link;
}
sum_dev2 = 0.0;
for (i = 0; i < n; i++) {
double mean = (double) N_FLOWS / n;
double deviation = histogram[i] - mean;
sum_dev2 += deviation * deviation;
}
stddev = sqrt(sum_dev2 / n);
disruption = (double) changed / N_FLOWS;
perfect = 1.0 / (n + 1);
distribution = stddev / ((double) N_FLOWS / n);
printf("%2d -> %2d: disruption=%.2f (perfect=%.2f); "
"stddev/expected=%.4f\n",
n, n + 1, disruption, perfect, distribution);
switch (ntohs(mp.algorithm)) {
case NX_MP_ALG_MODULO_N:
if (disruption < (n < 2 ? .25 : .5)) {
fprintf(stderr, "%d -> %d: disruption=%.2f < .5\n",
n, n + 1, disruption);
ok = false;
}
break;
case NX_MP_ALG_HASH_THRESHOLD:
if (disruption < .48 || disruption > .52) {
fprintf(stderr, "%d -> %d: disruption=%.2f not approximately "
".5\n", n, n + 1, disruption);
ok = false;
}
break;
case NX_MP_ALG_ITER_HASH:
if (!(n & (n - 1))) {
break;
}
/* Fall through. */
case NX_MP_ALG_HRW:
if (fabs(disruption - perfect) >= .01) {
fprintf(stderr, "%d -> %d: disruption=%.5f differs from "
"perfect=%.5f by more than .01\n",
n, n + 1, disruption, perfect);
ok = false;
}
break;
default:
NOT_REACHED();
}
}
return ok ? 0 : 1;
}
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