]>
git.proxmox.com Git - mirror_ovs.git/blob - tests/test-multipath.c
2 * Copyright (c) 2010, 2012 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 #include "multipath.h"
28 #include "ofp-actions.h"
33 main(int argc
, char *argv
[])
35 enum { MP_MAX_LINKS
= 63 };
36 struct ofpact_multipath mp
;
40 set_program_name(argv
[0]);
44 ovs_fatal(0, "usage: %s multipath_action", program_name
);
47 multipath_parse(&mp
, argv
[1]);
48 for (n
= 1; n
<= MP_MAX_LINKS
; n
++) {
49 enum { N_FLOWS
= 65536 };
50 double disruption
, perfect
, distribution
;
51 int histogram
[MP_MAX_LINKS
];
52 double sum_dev2
, stddev
;
57 memset(histogram
, 0, sizeof histogram
);
58 for (i
= 0; i
< N_FLOWS
; i
++) {
59 int old_link
, new_link
;
60 struct flow_wildcards wc
;
63 random_bytes(&flow
, sizeof flow
);
64 memset(flow
.zeros
, 0, sizeof flow
.zeros
);
68 multipath_execute(&mp
, &flow
, &wc
);
69 old_link
= flow
.regs
[0];
72 multipath_execute(&mp
, &flow
, &wc
);
73 new_link
= flow
.regs
[0];
75 assert(old_link
>= 0 && old_link
< n
);
76 assert(new_link
>= 0 && new_link
< n
+ 1);
78 histogram
[old_link
]++;
79 changed
+= old_link
!= new_link
;
83 for (i
= 0; i
< n
; i
++) {
84 double mean
= (double) N_FLOWS
/ n
;
85 double deviation
= histogram
[i
] - mean
;
87 sum_dev2
+= deviation
* deviation
;
89 stddev
= sqrt(sum_dev2
/ n
);
91 disruption
= (double) changed
/ N_FLOWS
;
92 perfect
= 1.0 / (n
+ 1);
93 distribution
= stddev
/ ((double) N_FLOWS
/ n
);
94 printf("%2d -> %2d: disruption=%.2f (perfect=%.2f); "
95 "stddev/expected=%.4f\n",
96 n
, n
+ 1, disruption
, perfect
, distribution
);
98 switch (mp
.algorithm
) {
99 case NX_MP_ALG_MODULO_N
:
100 if (disruption
< (n
< 2 ? .25 : .5)) {
101 fprintf(stderr
, "%d -> %d: disruption=%.2f < .5\n",
102 n
, n
+ 1, disruption
);
107 case NX_MP_ALG_HASH_THRESHOLD
:
108 if (disruption
< .48 || disruption
> .52) {
109 fprintf(stderr
, "%d -> %d: disruption=%.2f not approximately "
110 ".5\n", n
, n
+ 1, disruption
);
115 case NX_MP_ALG_ITER_HASH
:
116 if (!(n
& (n
- 1))) {
121 if (fabs(disruption
- perfect
) >= .01) {
122 fprintf(stderr
, "%d -> %d: disruption=%.5f differs from "
123 "perfect=%.5f by more than .01\n",
124 n
, n
+ 1, disruption
, perfect
);