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)
  36 {
  37     qemu_mutex_init(&stats->lock);
  38     if (qtest_enabled()) {
  39         clock_type = QEMU_CLOCK_VIRTUAL;
  40     }
  41 }
  42
  43 void 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
  50 void 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
  59 void 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
  77 BlockAcctTimedStats *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
  87 void 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 static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
  98                                  bool failed)
  99 {
 100     BlockAcctTimedStats *s;
 101     int64_t time_ns = qemu_clock_get_ns(clock_type);
 102     int64_t latency_ns = time_ns - cookie->start_time_ns;
 103
 104     if (qtest_enabled()) {
 105         latency_ns = qtest_latency_ns;
 106     }
 107
 108     assert(cookie->type < BLOCK_MAX_IOTYPE);
 109
 110     qemu_mutex_lock(&stats->lock);
 111
 112     if (failed) {
 113         stats->failed_ops[cookie->type]++;
 114     } else {
 115         stats->nr_bytes[cookie->type] += cookie->bytes;
 116         stats->nr_ops[cookie->type]++;
 117     }
 118
 119     if (!failed || stats->account_failed) {
 120         stats->total_time_ns[cookie->type] += latency_ns;
 121         stats->last_access_time_ns = time_ns;
 122
 123         QSLIST_FOREACH(s, &stats->intervals, entries) {
 124             timed_average_account(&s->latency[cookie->type], latency_ns);
 125         }
 126     }
 127
 128     qemu_mutex_unlock(&stats->lock);
 129 }
 130
 131 void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
 132 {
 133     block_account_one_io(stats, cookie, false);
 134 }
 135
 136 void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
 137 {
 138     block_account_one_io(stats, cookie, true);
 139 }
 140
 141 void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
 142 {
 143     assert(type < BLOCK_MAX_IOTYPE);
 144
 145     /* block_account_one_io() updates total_time_ns[], but this one does
 146      * not.  The reason is that invalid requests are accounted during their
 147      * submission, therefore there's no actual I/O involved.
 148      */
 149     qemu_mutex_lock(&stats->lock);
 150     stats->invalid_ops[type]++;
 151
 152     if (stats->account_invalid) {
 153         stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
 154     }
 155     qemu_mutex_unlock(&stats->lock);
 156 }
 157
 158 void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
 159                       int num_requests)
 160 {
 161     assert(type < BLOCK_MAX_IOTYPE);
 162
 163     qemu_mutex_lock(&stats->lock);
 164     stats->merged[type] += num_requests;
 165     qemu_mutex_unlock(&stats->lock);
 166 }
 167
 168 int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
 169 {
 170     return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
 171 }
 172
 173 double block_acct_queue_depth(BlockAcctTimedStats *stats,
 174                               enum BlockAcctType type)
 175 {
 176     uint64_t sum, elapsed;
 177
 178     assert(type < BLOCK_MAX_IOTYPE);
 179
 180     qemu_mutex_lock(&stats->stats->lock);
 181     sum = timed_average_sum(&stats->latency[type], &elapsed);
 182     qemu_mutex_unlock(&stats->stats->lock);
 183
 184     return (double) sum / elapsed;
 185 }