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 "qemu/osdep.h"
#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)
{
qemu_mutex_init(&stats->lock);
if (qtest_enabled()) {
clock_type = QEMU_CLOCK_VIRTUAL;
}
}
void block_acct_setup(BlockAcctStats *stats, bool account_invalid,
bool account_failed)
{
stats->account_invalid = account_invalid;
stats->account_failed = account_failed;
}
void block_acct_cleanup(BlockAcctStats *stats)
{
BlockAcctTimedStats *s, *next;
QSLIST_FOREACH_SAFE(s, &stats->intervals, entries, next) {
g_free(s);
}
qemu_mutex_destroy(&stats->lock);
}
void block_acct_add_interval(BlockAcctStats *stats, unsigned interval_length)
{
BlockAcctTimedStats *s;
unsigned i;
s = g_new0(BlockAcctTimedStats, 1);
s->interval_length = interval_length;
s->stats = stats;
qemu_mutex_lock(&stats->lock);
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);
}
qemu_mutex_unlock(&stats->lock);
}
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;
}
/* block_latency_histogram_compare_func:
* Compare @key with interval [@it[0], @it[1]).
* Return: -1 if @key < @it[0]
* 0 if @key in [@it[0], @it[1])
* +1 if @key >= @it[1]
*/
static int block_latency_histogram_compare_func(const void *key, const void *it)
{
uint64_t k = *(uint64_t *)key;
uint64_t a = ((uint64_t *)it)[0];
uint64_t b = ((uint64_t *)it)[1];
return k < a ? -1 : (k < b ? 0 : 1);
}
static void block_latency_histogram_account(BlockLatencyHistogram *hist,
int64_t latency_ns)
{
uint64_t *pos;
if (hist->bins == NULL) {
/* histogram disabled */
return;
}
if (latency_ns < hist->boundaries[0]) {
hist->bins[0]++;
return;
}
if (latency_ns >= hist->boundaries[hist->nbins - 2]) {
hist->bins[hist->nbins - 1]++;
return;
}
pos = bsearch(&latency_ns, hist->boundaries, hist->nbins - 2,
sizeof(hist->boundaries[0]),
block_latency_histogram_compare_func);
assert(pos != NULL);
hist->bins[pos - hist->boundaries + 1]++;
}
int block_latency_histogram_set(BlockAcctStats *stats, enum BlockAcctType type,
uint64List *boundaries)
{
BlockLatencyHistogram *hist = &stats->latency_histogram[type];
uint64List *entry;
uint64_t *ptr;
uint64_t prev = 0;
int new_nbins = 1;
for (entry = boundaries; entry; entry = entry->next) {
if (entry->value <= prev) {
return -EINVAL;
}
new_nbins++;
prev = entry->value;
}
hist->nbins = new_nbins;
g_free(hist->boundaries);
hist->boundaries = g_new(uint64_t, hist->nbins - 1);
for (entry = boundaries, ptr = hist->boundaries; entry;
entry = entry->next, ptr++)
{
*ptr = entry->value;
}
g_free(hist->bins);
hist->bins = g_new0(uint64_t, hist->nbins);
return 0;
}
void block_latency_histograms_clear(BlockAcctStats *stats)
{
int i;
for (i = 0; i < BLOCK_MAX_IOTYPE; i++) {
BlockLatencyHistogram *hist = &stats->latency_histogram[i];
g_free(hist->bins);
g_free(hist->boundaries);
memset(hist, 0, sizeof(*hist));
}
}
static void block_account_one_io(BlockAcctStats *stats, BlockAcctCookie *cookie,
bool 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;
}
assert(cookie->type < BLOCK_MAX_IOTYPE);
if (cookie->type == BLOCK_ACCT_NONE) {
return;
}
qemu_mutex_lock(&stats->lock);
if (failed) {
stats->failed_ops[cookie->type]++;
} else {
stats->nr_bytes[cookie->type] += cookie->bytes;
stats->nr_ops[cookie->type]++;
}
block_latency_histogram_account(&stats->latency_histogram[cookie->type],
latency_ns);
if (!failed || stats->account_failed) {
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);
}
}
qemu_mutex_unlock(&stats->lock);
cookie->type = BLOCK_ACCT_NONE;
}
void block_acct_done(BlockAcctStats *stats, BlockAcctCookie *cookie)
{
block_account_one_io(stats, cookie, false);
}
void block_acct_failed(BlockAcctStats *stats, BlockAcctCookie *cookie)
{
block_account_one_io(stats, cookie, true);
}
void block_acct_invalid(BlockAcctStats *stats, enum BlockAcctType type)
{
assert(type < BLOCK_MAX_IOTYPE);
/* block_account_one_io() updates 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.
*/
qemu_mutex_lock(&stats->lock);
stats->invalid_ops[type]++;
if (stats->account_invalid) {
stats->last_access_time_ns = qemu_clock_get_ns(clock_type);
}
qemu_mutex_unlock(&stats->lock);
}
void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
int num_requests)
{
assert(type < BLOCK_MAX_IOTYPE);
qemu_mutex_lock(&stats->lock);
stats->merged[type] += num_requests;
qemu_mutex_unlock(&stats->lock);
}
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);
qemu_mutex_lock(&stats->stats->lock);
sum = timed_average_sum(&stats->latency[type], &elapsed);
qemu_mutex_unlock(&stats->stats->lock);
return (double) sum / elapsed;
}