block/accounting.c

   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 "block/accounting.h"
  27 #include "block/block_int.h"
  28 #include "qemu/timer.h"
  29 #include "sysemu/qtest.h"
  30
  31 static QEMUClockType clock_type = QEMU_CLOCK_REALTIME;
  32 static const int qtest_latency_ns = NANOSECONDS_PER_SECOND / 1000;
  33
  34 void block_acct_init(BlockAcctStats *stats, bool account_invalid,
  35                      bool account_failed)
  36 {
  37     stats->account_invalid = account_invalid;
  38     stats->account_failed = account_failed;
  39
  40     if (qtest_enabled()) {
  41         clock_type = QEMU_CLOCK_VIRTUAL;
  42     }
  43 }
  44
  45 void block_acct_cleanup(BlockAcctStats *stats)
  46 {
  47     BlockAcctTimedStats *s, *next;
  48     QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
  49         g_free(s);
  50     }
  51 }
  52
  53 void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
  54 {
  55     BlockAcctTimedStats *s;
  56     unsigned i;
  57
  58     s = g_new0(BlockAcctTimedStats, 1);
  59     s->interval_length = interval_length;
  60     QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
  61
  62     for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
  63         timed_average_init(&s->latency[i], clock_type,
  64                            (uint64_t) interval_length * NANOSECONDS_PER_SECOND);
  65     }
  66 }
  67
  68 BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
  69                                               BlockAcctTimedStats *s)
  70 {
  71     if (s == NULL) {
  72         return QSLIST_FIRST(&stats->intervals);
  73     } else {
  74         return QSLIST_NEXT(s, entries);
  75     }
  76 }
  77
  78 void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
  79                       int64_t bytes, enum BlockAcctType type)
  80 {
  81     assert(type < BLOCK_MAX_IOTYPE);
  82
  83     cookie->bytes = bytes;
  84     cookie->start_time_ns = qemu_clock_get_ns(clock_type);
  85     cookie->type = type;
  86 }
  87
  88 void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
  89 {
  90     BlockAcctTimedStats *s;
  91     int64_t time_ns = qemu_clock_get_ns(clock_type);
  92     int64_t latency_ns = time_ns - cookie->start_time_ns;
  93
  94     if (qtest_enabled()) {
  95         latency_ns = qtest_latency_ns;
  96     }
  97
  98     assert(cookie->type < BLOCK_MAX_IOTYPE);
  99
 100     stats->nr_bytes[cookie->type] += cookie->bytes;
 101     stats->nr_ops[cookie->type]++;
 102     stats->total_time_ns[cookie->type] += latency_ns;
 103     stats->last_access_time_ns = time_ns;
 104
 105     QSLIST_FOREACH(s, &stats->intervals, entries) {
 106         timed_average_account(&s->latency[cookie->type], latency_ns);
 107     }
 108 }
 109
 110 void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
 111 {
 112     assert(cookie->type < BLOCK_MAX_IOTYPE);
 113
 114     stats->failed_ops[cookie->type]++;
 115
 116     if (stats->account_failed) {
 117         BlockAcctTimedStats *s;
 118         int64_t time_ns = qemu_clock_get_ns(clock_type);
 119         int64_t latency_ns = time_ns - cookie->start_time_ns;
 120
 121         if (qtest_enabled()) {
 122             latency_ns = qtest_latency_ns;
 123         }
 124
 125         stats->total_time_ns[cookie->type] += latency_ns;
 126         stats->last_access_time_ns = time_ns;
 127
 128         QSLIST_FOREACH(s, &stats->intervals, entries) {
 129             timed_average_account(&s->latency[cookie->type], latency_ns);
 130         }
 131     }
 132 }
 133
 134 void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
 135 {
 136     assert(type < BLOCK_MAX_IOTYPE);
 137
 138     /* block_acct_done() and block_acct_failed() update
 139      * total_time_ns[], but this one does not. The reason is that
 140      * invalid requests are accounted during their submission,
 141      * therefore there's no actual I/O involved. */
 142
 143     stats->invalid_ops[type]++;
 144
 145     if (stats->account_invalid) {
 146         stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
 147     }
 148 }
 149
 150 void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
 151                       int num_requests)
 152 {
 153     assert(type < BLOCK_MAX_IOTYPE);
 154     stats->merged[type] += num_requests;
 155 }
 156
 157 int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
 158 {
 159     return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
 160 }
 161
 162 double block_acct_queue_depth(BlockAcctTimedStats *stats,
 163                               enum BlockAcctType type)
 164 {
 165     uint64_t sum, elapsed;
 166
 167     assert(type < BLOCK_MAX_IOTYPE);
 168
 169     sum = timed_average_sum(&stats->latency[type], &elapsed);
 170
 171     return (double) sum / elapsed;
 172 }