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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/*
* Copyright (c) 2009, 2010, 2011, 2012 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 "coverage.h"
#include <inttypes.h>
#include <stdlib.h>
#include "dynamic-string.h"
#include "hash.h"
#include "timeval.h"
#include "unixctl.h"
#include "util.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(coverage);
/* The coverage counters. */
#if USE_LINKER_SECTIONS
extern struct coverage_counter *__start_coverage[];
extern struct coverage_counter *__stop_coverage[];
#define coverage_counters __start_coverage
#define n_coverage_counters (__stop_coverage - __start_coverage)
#else /* !USE_LINKER_SECTIONS */
#define COVERAGE_COUNTER(NAME) COVERAGE_DEFINE__(NAME);
#include "coverage.def"
#undef COVERAGE_COUNTER
struct coverage_counter *coverage_counters[] = {
#define COVERAGE_COUNTER(NAME) &counter_##NAME,
#include "coverage.def"
#undef COVERAGE_COUNTER
};
#define n_coverage_counters ARRAY_SIZE(coverage_counters)
#endif /* !USE_LINKER_SECTIONS */
static unsigned int epoch;
static void
coverage_unixctl_log(struct unixctl_conn *conn, int argc OVS_UNUSED,
const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
{
coverage_log(VLL_WARN, false);
unixctl_command_reply(conn, NULL);
}
void
coverage_init(void)
{
unixctl_command_register("coverage/log", "", 0, 0,
coverage_unixctl_log, NULL);
}
/* Sorts coverage counters in descending order by count, within equal counts
* alphabetically by name. */
static int
compare_coverage_counters(const void *a_, const void *b_)
{
const struct coverage_counter *const *ap = a_;
const struct coverage_counter *const *bp = b_;
const struct coverage_counter *a = *ap;
const struct coverage_counter *b = *bp;
if (a->count != b->count) {
return a->count < b->count ? 1 : -1;
} else {
return strcmp(a->name, b->name);
}
}
static uint32_t
coverage_hash(void)
{
struct coverage_counter **c;
uint32_t hash = 0;
int n_groups, i;
/* Sort coverage counters into groups with equal counts. */
c = xmalloc(n_coverage_counters * sizeof *c);
for (i = 0; i < n_coverage_counters; i++) {
c[i] = coverage_counters[i];
}
qsort(c, n_coverage_counters, sizeof *c, compare_coverage_counters);
/* Hash the names in each group along with the rank. */
n_groups = 0;
for (i = 0; i < n_coverage_counters; ) {
int j;
if (!c[i]->count) {
break;
}
n_groups++;
hash = hash_int(i, hash);
for (j = i; j < n_coverage_counters; j++) {
if (c[j]->count != c[i]->count) {
break;
}
hash = hash_string(c[j]->name, hash);
}
i = j;
}
free(c);
return hash_int(n_groups, hash);
}
static bool
coverage_hit(uint32_t hash)
{
enum { HIT_BITS = 1024, BITS_PER_WORD = 32 };
static uint32_t hit[HIT_BITS / BITS_PER_WORD];
BUILD_ASSERT_DECL(IS_POW2(HIT_BITS));
static long long int next_clear = LLONG_MIN;
unsigned int bit_index = hash & (HIT_BITS - 1);
unsigned int word_index = bit_index / BITS_PER_WORD;
unsigned int word_mask = 1u << (bit_index % BITS_PER_WORD);
/* Expire coverage hash suppression once a day. */
if (time_msec() >= next_clear) {
memset(hit, 0, sizeof hit);
next_clear = time_msec() + 60 * 60 * 24 * 1000LL;
}
if (hit[word_index] & word_mask) {
return true;
} else {
hit[word_index] |= word_mask;
return false;
}
}
static void
coverage_log_counter(enum vlog_level level, const struct coverage_counter *c)
{
VLOG(level, "%-24s %5u / %9llu", c->name, c->count, c->count + c->total);
}
/* Logs the coverage counters at the given vlog 'level'. If
* 'suppress_dups' is true, then duplicate events are not displayed.
* Care should be taken in the value used for 'level'. Depending on the
* configuration, syslog can write changes synchronously, which can
* cause the coverage messages to take several seconds to write. */
void
coverage_log(enum vlog_level level, bool suppress_dups)
{
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 3);
size_t n_never_hit;
uint32_t hash;
size_t i;
if (suppress_dups
? !vlog_is_enabled(THIS_MODULE, level)
: vlog_should_drop(THIS_MODULE, level, &rl)) {
return;
}
hash = coverage_hash();
if (suppress_dups) {
if (coverage_hit(hash)) {
VLOG(level, "Skipping details of duplicate event coverage for "
"hash=%08"PRIx32" in epoch %u", hash, epoch);
return;
}
}
n_never_hit = 0;
VLOG(level, "Event coverage (epoch %u/entire run), hash=%08"PRIx32":",
epoch, hash);
for (i = 0; i < n_coverage_counters; i++) {
struct coverage_counter *c = coverage_counters[i];
if (c->count) {
coverage_log_counter(level, c);
}
}
for (i = 0; i < n_coverage_counters; i++) {
struct coverage_counter *c = coverage_counters[i];
if (!c->count) {
if (c->total) {
coverage_log_counter(level, c);
} else {
n_never_hit++;
}
}
}
VLOG(level, "%zu events never hit", n_never_hit);
}
/* Advances to the next epoch of coverage, resetting all the counters to 0. */
void
coverage_clear(void)
{
size_t i;
epoch++;
for (i = 0; i < n_coverage_counters; i++) {
struct coverage_counter *c = coverage_counters[i];
c->total += c->count;
c->count = 0;
}
}
|
