block/accounting.c - qemu - Git at Google

 /*
  * 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;
 }
	/*
	* 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;
	}