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