xref: /qemu/block/accounting.c (revision 4f2d31fb) 
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 }
173