qemu/block/accounting.c

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/*
* QEMU System Emulator block accounting
*
* Copyright (c) 2011 Christoph Hellwig
* Copyright (c) 2015 Igalia, S.L.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "block/accounting.h"
#include "block/block_int.h"
#include "qemu/timer.h"
#include "sysemu/qtest.h"
static QEMUClockType clock_type = QEMU_CLOCK_REALTIME;
static const int qtest_latency_ns = NANOSECONDS_PER_SECOND / 1000;
void block_acct_init(BlockAcctStats *stats, bool account_invalid,
bool account_failed)
{
stats->account_invalid = account_invalid;
stats->account_failed = account_failed;
if (qtest_enabled()) {
clock_type = QEMU_CLOCK_VIRTUAL;
}
}
void block_acct_cleanup(BlockAcctStats *stats)
{
BlockAcctTimedStats *s, *next;
QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
g_free(s);
}
}
void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
{
BlockAcctTimedStats *s;
unsigned i;
s = g_new0(BlockAcctTimedStats, 1);
s->interval_length = interval_length;
QSLIST_INSERT_HEAD(&stats->intervals, s, entries);
for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
timed_average_init(&s->latency[i], clock_type,
(uint64_t) interval_length * NANOSECONDS_PER_SECOND);
}
}
BlockAcctTimedStats *block_acct_interval_next(BlockAcctStats *stats,
BlockAcctTimedStats *s)
{
if (s == NULL) {
return QSLIST_FIRST(&stats->intervals);
} else {
return QSLIST_NEXT(s, entries);
}
}
void block_acct_start(BlockAcctStats *stats, BlockAcctCookie *cookie,
int64_t bytes, enum BlockAcctType type)
{
assert(type < BLOCK_MAX_IOTYPE);
cookie->bytes = bytes;
cookie->start_time_ns = qemu_clock_get_ns(clock_type);
cookie->type = type;
}
void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
{
BlockAcctTimedStats *s;
int64_t time_ns = qemu_clock_get_ns(clock_type);
int64_t latency_ns = time_ns - cookie->start_time_ns;
if (qtest_enabled()) {
latency_ns = qtest_latency_ns;
}
assert(cookie->type < BLOCK_MAX_IOTYPE);
stats->nr_bytes[cookie->type] += cookie->bytes;
stats->nr_ops[cookie->type]++;
stats->total_time_ns[cookie->type] += latency_ns;
stats->last_access_time_ns = time_ns;
QSLIST_FOREACH(s, &stats->intervals, entries) {
timed_average_account(&s->latency[cookie->type], latency_ns);
}
}
void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
{
assert(cookie->type < BLOCK_MAX_IOTYPE);
stats->failed_ops[cookie->type]++;
if (stats->account_failed) {
BlockAcctTimedStats *s;
int64_t time_ns = qemu_clock_get_ns(clock_type);
int64_t latency_ns = time_ns - cookie->start_time_ns;
if (qtest_enabled()) {
latency_ns = qtest_latency_ns;
}
stats->total_time_ns[cookie->type] += latency_ns;
stats->last_access_time_ns = time_ns;
QSLIST_FOREACH(s, &stats->intervals, entries) {
timed_average_account(&s->latency[cookie->type], latency_ns);
}
}
}
void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
{
assert(type < BLOCK_MAX_IOTYPE);
/* block_acct_done() and block_acct_failed() update
* total_time_ns[], but this one does not. The reason is that
* invalid requests are accounted during their submission,
* therefore there's no actual I/O involved. */
stats->invalid_ops[type]++;
if (stats->account_invalid) {
stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
}
}
void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
int num_requests)
{
assert(type < BLOCK_MAX_IOTYPE);
stats->merged[type] += num_requests;
}
int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
{
return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
}
double block_acct_queue_depth(BlockAcctTimedStats *stats,
enum BlockAcctType type)
{
uint64_t sum, elapsed;
assert(type < BLOCK_MAX_IOTYPE);
sum = timed_average_sum(&stats->latency[type], &elapsed);
return (double) sum / elapsed;
}