xref: /openbmc/qemu/block/accounting.c (revision c79aa350)
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  
32  static QEMUClockType clock_type = QEMU_CLOCK_REALTIME;
33  static const int qtest_latency_ns = NANOSECONDS_PER_SECOND / 1000;
34  
35  void block_acct_init(BlockAcctStats *stats)
36  {
37      qemu_mutex_init(&stats->lock);
38      if (qtest_enabled()) {
39          clock_type = QEMU_CLOCK_VIRTUAL;
40      }
41      stats->account_invalid = true;
42      stats->account_failed = true;
43  }
44  
45  static bool bool_from_onoffauto(OnOffAuto val, bool def)
46  {
47      switch (val) {
48      case ON_OFF_AUTO_AUTO:
49          return def;
50      case ON_OFF_AUTO_ON:
51          return true;
52      case ON_OFF_AUTO_OFF:
53          return false;
54      default:
55          abort();
56      }
57  }
58  
59  void block_acct_setup(BlockAcctStats *stats, enum OnOffAuto account_invalid,
60                        enum OnOffAuto account_failed)
61  {
62      stats->account_invalid = bool_from_onoffauto(account_invalid,
63                                                   stats->account_invalid);
64      stats->account_failed = bool_from_onoffauto(account_failed,
65                                                  stats->account_failed);
66  }
67  
68  void block_acct_cleanup(BlockAcctStats *stats)
69  {
70      BlockAcctTimedStats *s, *next;
71      QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
72          g_free(s);
73      }
74      qemu_mutex_destroy(&stats->lock);
75  }
76  
77  void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
78  {
79      BlockAcctTimedStats *s;
80      unsigned i;
81  
82      s = g_new0(BlockAcctTimedStats, 1);
83      s->interval_length = interval_length;
84      s->stats = stats;
85      qemu_mutex_lock(&stats->lock);
86      QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
87  
88      for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
89          timed_average_init(&s->latency[i], clock_type,
90                             (uint64_t) interval_length * NANOSECONDS_PER_SECOND);
91      }
92      qemu_mutex_unlock(&stats->lock);
93  }
94  
95  BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
96                                                BlockAcctTimedStats *s)
97  {
98      if (s == NULL) {
99          return QSLIST_FIRST(&stats->intervals);
100      } else {
101          return QSLIST_NEXT(s, entries);
102      }
103  }
104  
105  void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
106                        int64_t bytes, enum BlockAcctType type)
107  {
108      assert(type < BLOCK_MAX_IOTYPE);
109  
110      cookie->bytes = bytes;
111      cookie->start_time_ns = qemu_clock_get_ns(clock_type);
112      cookie->type = type;
113  }
114  
115  /* block_latency_histogram_compare_func:
116   * Compare @key with interval [@it[0], @it[1]).
117   * Return: -1 if @key < @it[0]
118   *          0 if @key in [@it[0], @it[1])
119   *         +1 if @key >= @it[1]
120   */
121  static int block_latency_histogram_compare_func(const void *key, const void *it)
122  {
123      uint64_t k = *(uint64_t *)key;
124      uint64_t a = ((uint64_t *)it)[0];
125      uint64_t b = ((uint64_t *)it)[1];
126  
127      return k < a ? -1 : (k < b ? 0 : 1);
128  }
129  
130  static void block_latency_histogram_account(BlockLatencyHistogram *hist,
131                                              int64_t latency_ns)
132  {
133      uint64_t *pos;
134  
135      if (hist->bins == NULL) {
136          /* histogram disabled */
137          return;
138      }
139  
140  
141      if (latency_ns < hist->boundaries[0]) {
142          hist->bins[0]++;
143          return;
144      }
145  
146      if (latency_ns >= hist->boundaries[hist->nbins - 2]) {
147          hist->bins[hist->nbins - 1]++;
148          return;
149      }
150  
151      pos = bsearch(&latency_ns, hist->boundaries, hist->nbins - 2,
152                    sizeof(hist->boundaries[0]),
153                    block_latency_histogram_compare_func);
154      assert(pos != NULL);
155  
156      hist->bins[pos - hist->boundaries + 1]++;
157  }
158  
159  int block_latency_histogram_set(BlockAcctStats *stats, enum BlockAcctType type,
160                                  uint64List *boundaries)
161  {
162      BlockLatencyHistogram *hist = &stats->latency_histogram[type];
163      uint64List *entry;
164      uint64_t *ptr;
165      uint64_t prev = 0;
166      int new_nbins = 1;
167  
168      for (entry = boundaries; entry; entry = entry->next) {
169          if (entry->value <= prev) {
170              return -EINVAL;
171          }
172          new_nbins++;
173          prev = entry->value;
174      }
175  
176      hist->nbins = new_nbins;
177      g_free(hist->boundaries);
178      hist->boundaries = g_new(uint64_t, hist->nbins - 1);
179      for (entry = boundaries, ptr = hist->boundaries; entry;
180           entry = entry->next, ptr++)
181      {
182          *ptr = entry->value;
183      }
184  
185      g_free(hist->bins);
186      hist->bins = g_new0(uint64_t, hist->nbins);
187  
188      return 0;
189  }
190  
191  void block_latency_histograms_clear(BlockAcctStats *stats)
192  {
193      int i;
194  
195      for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
196          BlockLatencyHistogram *hist = &stats->latency_histogram[i];
197          g_free(hist->bins);
198          g_free(hist->boundaries);
199          memset(hist, 0, sizeof(*hist));
200      }
201  }
202  
203  static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
204                                   bool failed)
205  {
206      BlockAcctTimedStats *s;
207      int64_t time_ns = qemu_clock_get_ns(clock_type);
208      int64_t latency_ns = time_ns - cookie->start_time_ns;
209  
210      if (qtest_enabled()) {
211          latency_ns = qtest_latency_ns;
212      }
213  
214      assert(cookie->type < BLOCK_MAX_IOTYPE);
215  
216      if (cookie->type == BLOCK_ACCT_NONE) {
217          return;
218      }
219  
220      WITH_QEMU_LOCK_GUARD(&stats->lock) {
221          if (failed) {
222              stats->failed_ops[cookie->type]++;
223          } else {
224              stats->nr_bytes[cookie->type] += cookie->bytes;
225              stats->nr_ops[cookie->type]++;
226          }
227  
228          block_latency_histogram_account(&stats->latency_histogram[cookie->type],
229                                          latency_ns);
230  
231          if (!failed || stats->account_failed) {
232              stats->total_time_ns[cookie->type] += latency_ns;
233              stats->last_access_time_ns = time_ns;
234  
235              QSLIST_FOREACH(s, &stats->intervals, entries) {
236                  timed_average_account(&s->latency[cookie->type], latency_ns);
237              }
238          }
239      }
240  
241      cookie->type = BLOCK_ACCT_NONE;
242  }
243  
244  void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
245  {
246      block_account_one_io(stats, cookie, false);
247  }
248  
249  void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
250  {
251      block_account_one_io(stats, cookie, true);
252  }
253  
254  void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
255  {
256      assert(type < BLOCK_MAX_IOTYPE);
257  
258      /* block_account_one_io() updates total_time_ns[], but this one does
259       * not.  The reason is that invalid requests are accounted during their
260       * submission, therefore there's no actual I/O involved.
261       */
262      qemu_mutex_lock(&stats->lock);
263      stats->invalid_ops[type]++;
264  
265      if (stats->account_invalid) {
266          stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
267      }
268      qemu_mutex_unlock(&stats->lock);
269  }
270  
271  void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
272                        int num_requests)
273  {
274      assert(type < BLOCK_MAX_IOTYPE);
275  
276      qemu_mutex_lock(&stats->lock);
277      stats->merged[type] += num_requests;
278      qemu_mutex_unlock(&stats->lock);
279  }
280  
281  int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
282  {
283      return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
284  }
285  
286  double block_acct_queue_depth(BlockAcctTimedStats *stats,
287                                enum BlockAcctType type)
288  {
289      uint64_t sum, elapsed;
290  
291      assert(type < BLOCK_MAX_IOTYPE);
292  
293      qemu_mutex_lock(&stats->stats->lock);
294      sum = timed_average_sum(&stats->latency[type], &elapsed);
295      qemu_mutex_unlock(&stats->stats->lock);
296  
297      return (double) sum / elapsed;
298  }
299