qemu/block/accounting.c
Anton Nefedov f344446654 block: add empty account cookie type
Each block_acct_done/failed call is designed to correspond to a
previous block_acct_start call, which initializes the stats cookie.
However sometimes it is not the case, e.g. some error paths might
report the same cookie twice because it is hard to accurately track if
the cookie was reported yet or not.

This patch cleans the cookie after report.
(Note: block_acct_failed/done without a previous block_acct_start at
all should be avoided. Uninitialized cookie might hold a garbage value
and there is still "< BLOCK_MAX_IOTYPE" assertion for that)

It will be particularly useful in ide code where it's hard to
keep track whether the request done its accounting or not: in the
following patch of the series, trim requests will do the accounting
separately.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190923121737.83281-4-anton.nefedov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10 10:56:18 +02:00

283 lines
7.9 KiB
C

/*
* 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;
}