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 "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, bool account_invalid,
  36                      bool account_failed)
  37 {
  38     stats->account_invalid = account_invalid;
  39     stats->account_failed = account_failed;
  40
  41     if (qtest_enabled()) {
  42         clock_type = QEMU_CLOCK_VIRTUAL;
  43     }
  44 }
  45
  46 void block_acct_cleanup(BlockAcctStats *stats)
  47 {
  48     BlockAcctTimedStats *s, *next;
  49     QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
  50         g_free(s);
  51     }
  52 }
  53
  54 void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
  55 {
  56     BlockAcctTimedStats *s;
  57     unsigned i;
  58
  59     s = g_new0(BlockAcctTimedStats, 1);
  60     s->interval_length = interval_length;
  61     QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
  62
  63     for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
  64         timed_average_init(&s->latency[i], clock_type,
  65                            (uint64_t) interval_length * NANOSECONDS_PER_SECOND);
  66     }
  67 }
  68
  69 BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
  70                                               BlockAcctTimedStats *s)
  71 {
  72     if (s == NULL) {
  73         return QSLIST_FIRST(&stats->intervals);
  74     } else {
  75         return QSLIST_NEXT(s, entries);
  76     }
  77 }
  78
  79 void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
  80                       int64_t bytes, enum BlockAcctType type)
  81 {
  82     assert(type < BLOCK_MAX_IOTYPE);
  83
  84     cookie->bytes = bytes;
  85     cookie->start_time_ns = qemu_clock_get_ns(clock_type);
  86     cookie->type = type;
  87 }
  88
  89 void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
  90 {
  91     BlockAcctTimedStats *s;
  92     int64_t time_ns = qemu_clock_get_ns(clock_type);
  93     int64_t latency_ns = time_ns - cookie->start_time_ns;
  94
  95     if (qtest_enabled()) {
  96         latency_ns = qtest_latency_ns;
  97     }
  98
  99     assert(cookie->type < BLOCK_MAX_IOTYPE);
 100
 101     stats->nr_bytes[cookie->type] += cookie->bytes;
 102     stats->nr_ops[cookie->type]++;
 103     stats->total_time_ns[cookie->type] += latency_ns;
 104     stats->last_access_time_ns = time_ns;
 105
 106     QSLIST_FOREACH(s, &stats->intervals, entries) {
 107         timed_average_account(&s->latency[cookie->type], latency_ns);
 108     }
 109 }
 110
 111 void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
 112 {
 113     assert(cookie->type < BLOCK_MAX_IOTYPE);
 114
 115     stats->failed_ops[cookie->type]++;
 116
 117     if (stats->account_failed) {
 118         BlockAcctTimedStats *s;
 119         int64_t time_ns = qemu_clock_get_ns(clock_type);
 120         int64_t latency_ns = time_ns - cookie->start_time_ns;
 121
 122         if (qtest_enabled()) {
 123             latency_ns = qtest_latency_ns;
 124         }
 125
 126         stats->total_time_ns[cookie->type] += latency_ns;
 127         stats->last_access_time_ns = time_ns;
 128
 129         QSLIST_FOREACH(s, &stats->intervals, entries) {
 130             timed_average_account(&s->latency[cookie->type], latency_ns);
 131         }
 132     }
 133 }
 134
 135 void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
 136 {
 137     assert(type < BLOCK_MAX_IOTYPE);
 138
 139     /* block_acct_done() and block_acct_failed() update
 140      * total_time_ns[], but this one does not. The reason is that
 141      * invalid requests are accounted during their submission,
 142      * therefore there's no actual I/O involved. */
 143
 144     stats->invalid_ops[type]++;
 145
 146     if (stats->account_invalid) {
 147         stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
 148     }
 149 }
 150
 151 void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
 152                       int num_requests)
 153 {
 154     assert(type < BLOCK_MAX_IOTYPE);
 155     stats->merged[type] += num_requests;
 156 }
 157
 158 int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
 159 {
 160     return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
 161 }
 162
 163 double block_acct_queue_depth(BlockAcctTimedStats *stats,
 164                               enum BlockAcctType type)
 165 {
 166     uint64_t sum, elapsed;
 167
 168     assert(type < BLOCK_MAX_IOTYPE);
 169
 170     sum = timed_average_sum(&stats->latency[type], &elapsed);
 171
 172     return (double) sum / elapsed;
 173 }