block/accounting.c

   1 /*
   2  * QEMU System Emulator block accounting
   3  *
   4  * Copyright (c) 2011 Christoph Hellwig
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "block/accounting.h"
  26 #include "block/block_int.h"
  27 #include "qemu/timer.h"
  28
  29 static QEMUClockType clock_type = QEMU_CLOCK_REALTIME;
  30
  31 void block_acct_init(BlockAcctStats *stats, bool account_invalid,
  32                      bool account_failed)
  33 {
  34     stats->account_invalid = account_invalid;
  35     stats->account_failed = account_failed;
  36 }
  37
  38 void block_acct_cleanup(BlockAcctStats *stats)
  39 {
  40     BlockAcctTimedStats *s, *next;
  41     QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
  42         g_free(s);
  43     }
  44 }
  45
  46 void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
  47 {
  48     BlockAcctTimedStats *s;
  49     unsigned i;
  50
  51     s = g_new0(BlockAcctTimedStats, 1);
  52     s->interval_length = interval_length;
  53     QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
  54
  55     for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
  56         timed_average_init(&s->latency[i], clock_type,
  57                            (uint64_t) interval_length * NANOSECONDS_PER_SECOND);
  58     }
  59 }
  60
  61 BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
  62                                               BlockAcctTimedStats *s)
  63 {
  64     if (s == NULL) {
  65         return QSLIST_FIRST(&stats->intervals);
  66     } else {
  67         return QSLIST_NEXT(s, entries);
  68     }
  69 }
  70
  71 void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
  72                       int64_t bytes, enum BlockAcctType type)
  73 {
  74     assert(type < BLOCK_MAX_IOTYPE);
  75
  76     cookie->bytes = bytes;
  77     cookie->start_time_ns = qemu_clock_get_ns(clock_type);
  78     cookie->type = type;
  79 }
  80
  81 void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
  82 {
  83     BlockAcctTimedStats *s;
  84     int64_t time_ns = qemu_clock_get_ns(clock_type);
  85     int64_t latency_ns = time_ns - cookie->start_time_ns;
  86
  87     assert(cookie->type < BLOCK_MAX_IOTYPE);
  88
  89     stats->nr_bytes[cookie->type] += cookie->bytes;
  90     stats->nr_ops[cookie->type]++;
  91     stats->total_time_ns[cookie->type] += latency_ns;
  92     stats->last_access_time_ns = time_ns;
  93
  94     QSLIST_FOREACH(s, &stats->intervals, entries) {
  95         timed_average_account(&s->latency[cookie->type], latency_ns);
  96     }
  97 }
  98
  99 void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
 100 {
 101     assert(cookie->type < BLOCK_MAX_IOTYPE);
 102
 103     stats->failed_ops[cookie->type]++;
 104
 105     if (stats->account_failed) {
 106         BlockAcctTimedStats *s;
 107         int64_t time_ns = qemu_clock_get_ns(clock_type);
 108         int64_t latency_ns = time_ns - cookie->start_time_ns;
 109
 110         stats->total_time_ns[cookie->type] += latency_ns;
 111         stats->last_access_time_ns = time_ns;
 112
 113         QSLIST_FOREACH(s, &stats->intervals, entries) {
 114             timed_average_account(&s->latency[cookie->type], latency_ns);
 115         }
 116     }
 117 }
 118
 119 void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
 120 {
 121     assert(type < BLOCK_MAX_IOTYPE);
 122
 123     /* block_acct_done() and block_acct_failed() update
 124      * total_time_ns[], but this one does not. The reason is that
 125      * invalid requests are accounted during their submission,
 126      * therefore there's no actual I/O involved. */
 127
 128     stats->invalid_ops[type]++;
 129
 130     if (stats->account_invalid) {
 131         stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
 132     }
 133 }
 134
 135 void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
 136                       int num_requests)
 137 {
 138     assert(type < BLOCK_MAX_IOTYPE);
 139     stats->merged[type] += num_requests;
 140 }
 141
 142 int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
 143 {
 144     return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
 145 }
 146
 147 double block_acct_queue_depth(BlockAcctTimedStats *stats,
 148                               enum BlockAcctType type)
 149 {
 150     uint64_t sum, elapsed;
 151
 152     assert(type < BLOCK_MAX_IOTYPE);
 153
 154     sum = timed_average_sum(&stats->latency[type], &elapsed);
 155
 156     return (double) sum / elapsed;
 157 }