1/*
2 * QEMU System Emulator block accounting
3 *
4 * Copyright (c) 2011 Christoph Hellwig
5 * Copyright (c) 2015 Igalia, S.L.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26#include "qemu/osdep.h"
27#include "block/accounting.h"
28#include "block/block_int.h"
29#include "qemu/timer.h"
30#include "sysemu/qtest.h"
31
32static QEMUClockType clock_type = QEMU_CLOCK_REALTIME;
33static const int qtest_latency_ns = NANOSECONDS_PER_SECOND / 1000;
34
35void block_acct_init(BlockAcctStats *stats)
36{
37 qemu_mutex_init(&stats->lock);
38 if (qtest_enabled()) {
39 clock_type = QEMU_CLOCK_VIRTUAL;
40 }
41}
42
43void block_acct_setup(BlockAcctStats *stats, bool account_invalid,
44 bool account_failed)
45{
46 stats->account_invalid = account_invalid;
47 stats->account_failed = account_failed;
48}
49
50void block_acct_cleanup(BlockAcctStats *stats)
51{
52 BlockAcctTimedStats *s, *next;
53 QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
54 g_free(s);
55 }
56 qemu_mutex_destroy(&stats->lock);
57}
58
59void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
60{
61 BlockAcctTimedStats *s;
62 unsigned i;
63
64 s = g_new0(BlockAcctTimedStats, 1);
65 s->interval_length = interval_length;
66 s->stats = stats;
67 qemu_mutex_lock(&stats->lock);
68 QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
69
70 for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
71 timed_average_init(&s->latency[i], clock_type,
72 (uint64_t) interval_length * NANOSECONDS_PER_SECOND);
73 }
74 qemu_mutex_unlock(&stats->lock);
75}
76
77BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
78 BlockAcctTimedStats *s)
79{
80 if (s == NULL) {
81 return QSLIST_FIRST(&stats->intervals);
82 } else {
83 return QSLIST_NEXT(s, entries);
84 }
85}
86
87void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
88 int64_t bytes, enum BlockAcctType type)
89{
90 assert(type < BLOCK_MAX_IOTYPE);
91
92 cookie->bytes = bytes;
93 cookie->start_time_ns = qemu_clock_get_ns(clock_type);
94 cookie->type = type;
95}
96
97/* block_latency_histogram_compare_func:
98 * Compare @key with interval [@it[0], @it[1]).
99 * Return: -1 if @key < @it[0]
100 * 0 if @key in [@it[0], @it[1])
101 * +1 if @key >= @it[1]
102 */
103static int block_latency_histogram_compare_func(const void *key, const void *it)
104{
105 uint64_t k = *(uint64_t *)key;
106 uint64_t a = ((uint64_t *)it)[0];
107 uint64_t b = ((uint64_t *)it)[1];
108
109 return k < a ? -1 : (k < b ? 0 : 1);
110}
111
112static void block_latency_histogram_account(BlockLatencyHistogram *hist,
113 int64_t latency_ns)
114{
115 uint64_t *pos;
116
117 if (hist->bins == NULL) {
118 /* histogram disabled */
119 return;
120 }
121
122
123 if (latency_ns < hist->boundaries[0]) {
124 hist->bins[0]++;
125 return;
126 }
127
128 if (latency_ns >= hist->boundaries[hist->nbins - 2]) {
129 hist->bins[hist->nbins - 1]++;
130 return;
131 }
132
133 pos = bsearch(&latency_ns, hist->boundaries, hist->nbins - 2,
134 sizeof(hist->boundaries[0]),
135 block_latency_histogram_compare_func);
136 assert(pos != NULL);
137
138 hist->bins[pos - hist->boundaries + 1]++;
139}
140
141int block_latency_histogram_set(BlockAcctStats *stats, enum BlockAcctType type,
142 uint64List *boundaries)
143{
144 BlockLatencyHistogram *hist = &stats->latency_histogram[type];
145 uint64List *entry;
146 uint64_t *ptr;
147 uint64_t prev = 0;
148 int new_nbins = 1;
149
150 for (entry = boundaries; entry; entry = entry->next) {
151 if (entry->value <= prev) {
152 return -EINVAL;
153 }
154 new_nbins++;
155 prev = entry->value;
156 }
157
158 hist->nbins = new_nbins;
159 g_free(hist->boundaries);
160 hist->boundaries = g_new(uint64_t, hist->nbins - 1);
161 for (entry = boundaries, ptr = hist->boundaries; entry;
162 entry = entry->next, ptr++)
163 {
164 *ptr = entry->value;
165 }
166
167 g_free(hist->bins);
168 hist->bins = g_new0(uint64_t, hist->nbins);
169
170 return 0;
171}
172
173void block_latency_histograms_clear(BlockAcctStats *stats)
174{
175 int i;
176
177 for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
178 BlockLatencyHistogram *hist = &stats->latency_histogram[i];
179 g_free(hist->bins);
180 g_free(hist->boundaries);
181 memset(hist, 0, sizeof(*hist));
182 }
183}
184
185static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
186 bool failed)
187{
188 BlockAcctTimedStats *s;
189 int64_t time_ns = qemu_clock_get_ns(clock_type);
190 int64_t latency_ns = time_ns - cookie->start_time_ns;
191
192 if (qtest_enabled()) {
193 latency_ns = qtest_latency_ns;
194 }
195
196 assert(cookie->type < BLOCK_MAX_IOTYPE);
197
198 qemu_mutex_lock(&stats->lock);
199
200 if (failed) {
201 stats->failed_ops[cookie->type]++;
202 } else {
203 stats->nr_bytes[cookie->type] += cookie->bytes;
204 stats->nr_ops[cookie->type]++;
205 }
206
207 block_latency_histogram_account(&stats->latency_histogram[cookie->type],
208 latency_ns);
209
210 if (!failed || stats->account_failed) {
211 stats->total_time_ns[cookie->type] += latency_ns;
212 stats->last_access_time_ns = time_ns;
213
214 QSLIST_FOREACH(s, &stats->intervals, entries) {
215 timed_average_account(&s->latency[cookie->type], latency_ns);
216 }
217 }
218
219 qemu_mutex_unlock(&stats->lock);
220}
221
222void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
223{
224 block_account_one_io(stats, cookie, false);
225}
226
227void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
228{
229 block_account_one_io(stats, cookie, true);
230}
231
232void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
233{
234 assert(type < BLOCK_MAX_IOTYPE);
235
236 /* block_account_one_io() updates total_time_ns[], but this one does
237 * not. The reason is that invalid requests are accounted during their
238 * submission, therefore there's no actual I/O involved.
239 */
240 qemu_mutex_lock(&stats->lock);
241 stats->invalid_ops[type]++;
242
243 if (stats->account_invalid) {
244 stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
245 }
246 qemu_mutex_unlock(&stats->lock);
247}
248
249void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
250 int num_requests)
251{
252 assert(type < BLOCK_MAX_IOTYPE);
253
254 qemu_mutex_lock(&stats->lock);
255 stats->merged[type] += num_requests;
256 qemu_mutex_unlock(&stats->lock);
257}
258
259int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
260{
261 return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
262}
263
264double block_acct_queue_depth(BlockAcctTimedStats *stats,
265 enum BlockAcctType type)
266{
267 uint64_t sum, elapsed;
268
269 assert(type < BLOCK_MAX_IOTYPE);
270
271 qemu_mutex_lock(&stats->stats->lock);
272 sum = timed_average_sum(&stats->latency[type], &elapsed);
273 qemu_mutex_unlock(&stats->stats->lock);
274
275 return (double) sum / elapsed;
276}
277