tools/perf/util/ordered-events.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 #include <errno.h>
 #include <inttypes.h>
 #include <linux/list.h>
 #include <linux/compiler.h>
 #include <linux/string.h>
 #include "ordered-events.h"
 #include "session.h"
 #include "asm/bug.h"
 #include "debug.h"

 #define pr_N(n, fmt, ...) \
 	eprintf(n, debug_ordered_events, fmt, ##__VA_ARGS__)

 #define pr(fmt, ...) pr_N(1, pr_fmt(fmt), ##__VA_ARGS__)

 static void queue_event(struct ordered_events *oe, struct ordered_event *new)
 {
 	struct ordered_event *last = oe->last;
 	u64 timestamp = new->timestamp;
 	struct list_head *p;

 	++oe->nr_events;
 	oe->last = new;

 	pr_oe_time2(timestamp, "queue_event nr_events %u\n", oe->nr_events);

 	if (!last) {
 		list_add(&new->list, &oe->events);
 		oe->max_timestamp = timestamp;
 		return;
 	}

 	/*
 	 * last event might point to some random place in the list as it's
 	 * the last queued event. We expect that the new event is close to
 	 * this.
 	 */
 	if (last->timestamp <= timestamp) {
 		while (last->timestamp <= timestamp) {
 			p = last->list.next;
 			if (p == &oe->events) {
 				list_add_tail(&new->list, &oe->events);
 				oe->max_timestamp = timestamp;
 				return;
 			}
 			last = list_entry(p, struct ordered_event, list);
 		}
 		list_add_tail(&new->list, &last->list);
 	} else {
 		while (last->timestamp > timestamp) {
 			p = last->list.prev;
 			if (p == &oe->events) {
 				list_add(&new->list, &oe->events);
 				return;
 			}
 			last = list_entry(p, struct ordered_event, list);
 		}
 		list_add(&new->list, &last->list);
 	}
 }

 static union perf_event *__dup_event(struct ordered_events *oe,
 				     union perf_event *event)
 {
 	union perf_event *new_event = NULL;

 	if (oe->cur_alloc_size < oe->max_alloc_size) {
 		new_event = memdup(event, event->header.size);
 		if (new_event)
 			oe->cur_alloc_size += event->header.size;
 	}

 	return new_event;
 }

 static union perf_event *dup_event(struct ordered_events *oe,
 				   union perf_event *event)
 {
 	return oe->copy_on_queue ? __dup_event(oe, event) : event;
 }

 static void __free_dup_event(struct ordered_events *oe, union perf_event *event)
 {
 	if (event) {
 		oe->cur_alloc_size -= event->header.size;
 		free(event);
 	}
 }

 static void free_dup_event(struct ordered_events *oe, union perf_event *event)
 {
 	if (oe->copy_on_queue)
 		__free_dup_event(oe, event);
 }

 #define MAX_SAMPLE_BUFFER	(64 * 1024 / sizeof(struct ordered_event))
 static struct ordered_event *alloc_event(struct ordered_events *oe,
 					 union perf_event *event)
 {
 	struct list_head *cache = &oe->cache;
 	struct ordered_event *new = NULL;
 	union perf_event *new_event;
 	size_t size;

 	new_event = dup_event(oe, event);
 	if (!new_event)
 		return NULL;

 	/*
 	 * We maintain the following scheme of buffers for ordered
 	 * event allocation:
 	 *
 	 *   to_free list -> buffer1 (64K)
 	 *                   buffer2 (64K)
 	 *                   ...
 	 *
 	 * Each buffer keeps an array of ordered events objects:
 	 *    buffer -> event[0]
 	 *              event[1]
 	 *              ...
 	 *
 	 * Each allocated ordered event is linked to one of
 	 * following lists:
 	 *   - time ordered list 'events'
 	 *   - list of currently removed events 'cache'
 	 *
 	 * Allocation of the ordered event uses the following order
 	 * to get the memory:
 	 *   - use recently removed object from 'cache' list
 	 *   - use available object in current allocation buffer
 	 *   - allocate new buffer if the current buffer is full
 	 *
 	 * Removal of ordered event object moves it from events to
 	 * the cache list.
 	 */
 	size = sizeof(*oe->buffer) + MAX_SAMPLE_BUFFER * sizeof(*new);

 	if (!list_empty(cache)) {
 		new = list_entry(cache->next, struct ordered_event, list);
 		list_del(&new->list);
 	} else if (oe->buffer) {
 		new = &oe->buffer->event[oe->buffer_idx];
 		if (++oe->buffer_idx == MAX_SAMPLE_BUFFER)
 			oe->buffer = NULL;
 	} else if ((oe->cur_alloc_size + size) < oe->max_alloc_size) {
 		oe->buffer = malloc(size);
 		if (!oe->buffer) {
 			free_dup_event(oe, new_event);
 			return NULL;
 		}

 		pr("alloc size %" PRIu64 "B (+%zu), max %" PRIu64 "B\n",
 		   oe->cur_alloc_size, size, oe->max_alloc_size);

 		oe->cur_alloc_size += size;
 		list_add(&oe->buffer->list, &oe->to_free);

 		oe->buffer_idx = 1;
 		new = &oe->buffer->event[0];
 	} else {
 		pr("allocation limit reached %" PRIu64 "B\n", oe->max_alloc_size);
 		return NULL;
 	}

 	new->event = new_event;
 	return new;
 }

 static struct ordered_event *
 ordered_events__new_event(struct ordered_events *oe, u64 timestamp,
 		    union perf_event *event)
 {
 	struct ordered_event *new;

 	new = alloc_event(oe, event);
 	if (new) {
 		new->timestamp = timestamp;
 		queue_event(oe, new);
 	}

 	return new;
 }

 void ordered_events__delete(struct ordered_events *oe, struct ordered_event *event)
 {
 	list_move(&event->list, &oe->cache);
 	oe->nr_events--;
 	free_dup_event(oe, event->event);
 	event->event = NULL;
 }

 int ordered_events__queue(struct ordered_events *oe, union perf_event *event,
 			  u64 timestamp, u64 file_offset)
 {
 	struct ordered_event *oevent;

 	if (!timestamp || timestamp == ~0ULL)
 		return -ETIME;

 	if (timestamp < oe->last_flush) {
 		pr_oe_time(timestamp,      "out of order event\n");
 		pr_oe_time(oe->last_flush, "last flush, last_flush_type %d\n",
 			   oe->last_flush_type);

 		oe->nr_unordered_events++;
 	}

 	oevent = ordered_events__new_event(oe, timestamp, event);
 	if (!oevent) {
 		ordered_events__flush(oe, OE_FLUSH__HALF);
 		oevent = ordered_events__new_event(oe, timestamp, event);
 	}

 	if (!oevent)
 		return -ENOMEM;

 	oevent->file_offset = file_offset;
 	return 0;
 }

 static int do_flush(struct ordered_events *oe, bool show_progress)
 {
 	struct list_head *head = &oe->events;
 	struct ordered_event *tmp, *iter;
 	u64 limit = oe->next_flush;
 	u64 last_ts = oe->last ? oe->last->timestamp : 0ULL;
 	struct ui_progress prog;
 	int ret;

 	if (!limit)
 		return 0;

 	if (show_progress)
 		ui_progress__init(&prog, oe->nr_events, "Processing time ordered events...");

 	list_for_each_entry_safe(iter, tmp, head, list) {
 		if (session_done())
 			return 0;

 		if (iter->timestamp > limit)
 			break;
 		ret = oe->deliver(oe, iter);
 		if (ret)
 			return ret;

 		ordered_events__delete(oe, iter);
 		oe->last_flush = iter->timestamp;

 		if (show_progress)
 			ui_progress__update(&prog, 1);
 	}

 	if (list_empty(head))
 		oe->last = NULL;
 	else if (last_ts <= limit)
 		oe->last = list_entry(head->prev, struct ordered_event, list);

 	if (show_progress)
 		ui_progress__finish();

 	return 0;
 }

 static int __ordered_events__flush(struct ordered_events *oe, enum oe_flush how,
 				   u64 timestamp)
 {
 	static const char * const str[] = {
 		"NONE",
 		"FINAL",
 		"ROUND",
 		"HALF ",
 	};
 	int err;
 	bool show_progress = false;

 	if (oe->nr_events == 0)
 		return 0;

 	switch (how) {
 	case OE_FLUSH__FINAL:
 		show_progress = true;
 		__fallthrough;
 	case OE_FLUSH__TOP:
 		oe->next_flush = ULLONG_MAX;
 		break;

 	case OE_FLUSH__HALF:
 	{
 		struct ordered_event *first, *last;
 		struct list_head *head = &oe->events;

 		first = list_entry(head->next, struct ordered_event, list);
 		last = oe->last;

 		/* Warn if we are called before any event got allocated. */
 		if (WARN_ONCE(!last || list_empty(head), "empty queue"))
 			return 0;

 		oe->next_flush  = first->timestamp;
 		oe->next_flush += (last->timestamp - first->timestamp) / 2;
 		break;
 	}

 	case OE_FLUSH__TIME:
 		oe->next_flush = timestamp;
 		show_progress = false;
 		break;

 	case OE_FLUSH__ROUND:
 	case OE_FLUSH__NONE:
 	default:
 		break;
 	};

 	pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush PRE  %s, nr_events %u\n",
 		   str[how], oe->nr_events);
 	pr_oe_time(oe->max_timestamp, "max_timestamp\n");

 	err = do_flush(oe, show_progress);

 	if (!err) {
 		if (how == OE_FLUSH__ROUND)
 			oe->next_flush = oe->max_timestamp;

 		oe->last_flush_type = how;
 	}

 	pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush POST %s, nr_events %u\n",
 		   str[how], oe->nr_events);
 	pr_oe_time(oe->last_flush, "last_flush\n");

 	return err;
 }

 int ordered_events__flush(struct ordered_events *oe, enum oe_flush how)
 {
 	return __ordered_events__flush(oe, how, 0);
 }

 int ordered_events__flush_time(struct ordered_events *oe, u64 timestamp)
 {
 	return __ordered_events__flush(oe, OE_FLUSH__TIME, timestamp);
 }

 u64 ordered_events__first_time(struct ordered_events *oe)
 {
 	struct ordered_event *event;

 	if (list_empty(&oe->events))
 		return 0;

 	event = list_first_entry(&oe->events, struct ordered_event, list);
 	return event->timestamp;
 }

 void ordered_events__init(struct ordered_events *oe, ordered_events__deliver_t deliver,
 			  void *data)
 {
 	INIT_LIST_HEAD(&oe->events);
 	INIT_LIST_HEAD(&oe->cache);
 	INIT_LIST_HEAD(&oe->to_free);
 	oe->max_alloc_size = (u64) -1;
 	oe->cur_alloc_size = 0;
 	oe->deliver	   = deliver;
 	oe->data	   = data;
 }

 static void
 ordered_events_buffer__free(struct ordered_events_buffer *buffer,
 			    unsigned int max, struct ordered_events *oe)
 {
 	if (oe->copy_on_queue) {
 		unsigned int i;

 		for (i = 0; i < max; i++)
 			__free_dup_event(oe, buffer->event[i].event);
 	}

 	free(buffer);
 }

 void ordered_events__free(struct ordered_events *oe)
 {
 	struct ordered_events_buffer *buffer, *tmp;

 	if (list_empty(&oe->to_free))
 		return;

 	/*
 	 * Current buffer might not have all the events allocated
 	 * yet, we need to free only allocated ones ...
 	 */
 	list_del(&oe->buffer->list);
 	ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe);

 	/* ... and continue with the rest */
 	list_for_each_entry_safe(buffer, tmp, &oe->to_free, list) {
 		list_del(&buffer->list);
 		ordered_events_buffer__free(buffer, MAX_SAMPLE_BUFFER, oe);
 	}
 }

 void ordered_events__reinit(struct ordered_events *oe)
 {
 	ordered_events__deliver_t old_deliver = oe->deliver;

 	ordered_events__free(oe);
 	memset(oe, '\0', sizeof(*oe));
 	ordered_events__init(oe, old_deliver, oe->data);
 }
	// SPDX-License-Identifier: GPL-2.0
	#include <errno.h>
	#include <inttypes.h>
	#include <linux/list.h>
	#include <linux/compiler.h>
	#include <linux/string.h>
	#include "ordered-events.h"
	#include "session.h"
	#include "asm/bug.h"
	#include "debug.h"

	#define pr_N(n, fmt, ...) \
	eprintf(n, debug_ordered_events, fmt, ##__VA_ARGS__)

	#define pr(fmt, ...) pr_N(1, pr_fmt(fmt), ##__VA_ARGS__)

	static void queue_event(struct ordered_events oe, struct ordered_event new)
	{
	struct ordered_event *last = oe->last;
	u64 timestamp = new->timestamp;
	struct list_head *p;

	++oe->nr_events;
	oe->last = new;

	pr_oe_time2(timestamp, "queue_event nr_events %u\n", oe->nr_events);

	if (!last) {
	list_add(&new->list, &oe->events);
	oe->max_timestamp = timestamp;
	return;
	}

	/*
	* last event might point to some random place in the list as it's
	* the last queued event. We expect that the new event is close to
	* this.
	*/
	if (last->timestamp <= timestamp) {
	while (last->timestamp <= timestamp) {
	p = last->list.next;
	if (p == &oe->events) {
	list_add_tail(&new->list, &oe->events);
	oe->max_timestamp = timestamp;
	return;
	}
	last = list_entry(p, struct ordered_event, list);
	}
	list_add_tail(&new->list, &last->list);
	} else {
	while (last->timestamp > timestamp) {
	p = last->list.prev;
	if (p == &oe->events) {
	list_add(&new->list, &oe->events);
	return;
	}
	last = list_entry(p, struct ordered_event, list);
	}
	list_add(&new->list, &last->list);
	}
	}

	static union perf_event __dup_event(struct ordered_events oe,
	union perf_event *event)
	{
	union perf_event *new_event = NULL;

	if (oe->cur_alloc_size < oe->max_alloc_size) {
	new_event = memdup(event, event->header.size);
	if (new_event)
	oe->cur_alloc_size += event->header.size;
	}

	return new_event;
	}

	static union perf_event dup_event(struct ordered_events oe,
	union perf_event *event)
	{
	return oe->copy_on_queue ? __dup_event(oe, event) : event;
	}

	static void __free_dup_event(struct ordered_events oe, union perf_event event)
	{
	if (event) {
	oe->cur_alloc_size -= event->header.size;
	free(event);
	}
	}

	static void free_dup_event(struct ordered_events oe, union perf_event event)
	{
	if (oe->copy_on_queue)
	__free_dup_event(oe, event);
	}

	#define MAX_SAMPLE_BUFFER (64 * 1024 / sizeof(struct ordered_event))
	static struct ordered_event alloc_event(struct ordered_events oe,
	union perf_event *event)
	{
	struct list_head *cache = &oe->cache;
	struct ordered_event *new = NULL;
	union perf_event *new_event;
	size_t size;

	new_event = dup_event(oe, event);
	if (!new_event)
	return NULL;

	/*
	* We maintain the following scheme of buffers for ordered
	* event allocation:
	*
	* to_free list -> buffer1 (64K)
	* buffer2 (64K)
	* ...
	*
	* Each buffer keeps an array of ordered events objects:
	* buffer -> event[0]
	* event[1]
	* ...
	*
	* Each allocated ordered event is linked to one of
	* following lists:
	* - time ordered list 'events'
	* - list of currently removed events 'cache'
	*
	* Allocation of the ordered event uses the following order
	* to get the memory:
	* - use recently removed object from 'cache' list
	* - use available object in current allocation buffer
	* - allocate new buffer if the current buffer is full
	*
	* Removal of ordered event object moves it from events to
	* the cache list.
	*/
	size = sizeof(oe->buffer) + MAX_SAMPLE_BUFFER sizeof(*new);

	if (!list_empty(cache)) {
	new = list_entry(cache->next, struct ordered_event, list);
	list_del(&new->list);
	} else if (oe->buffer) {
	new = &oe->buffer->event[oe->buffer_idx];
	if (++oe->buffer_idx == MAX_SAMPLE_BUFFER)
	oe->buffer = NULL;
	} else if ((oe->cur_alloc_size + size) < oe->max_alloc_size) {
	oe->buffer = malloc(size);
	if (!oe->buffer) {
	free_dup_event(oe, new_event);
	return NULL;
	}

	pr("alloc size %" PRIu64 "B (+%zu), max %" PRIu64 "B\n",
	oe->cur_alloc_size, size, oe->max_alloc_size);

	oe->cur_alloc_size += size;
	list_add(&oe->buffer->list, &oe->to_free);

	oe->buffer_idx = 1;
	new = &oe->buffer->event[0];
	} else {
	pr("allocation limit reached %" PRIu64 "B\n", oe->max_alloc_size);
	return NULL;
	}

	new->event = new_event;
	return new;
	}

	static struct ordered_event *
	ordered_events__new_event(struct ordered_events *oe, u64 timestamp,
	union perf_event *event)
	{
	struct ordered_event *new;

	new = alloc_event(oe, event);
	if (new) {
	new->timestamp = timestamp;
	queue_event(oe, new);
	}

	return new;
	}

	void ordered_events__delete(struct ordered_events oe, struct ordered_event event)
	{
	list_move(&event->list, &oe->cache);
	oe->nr_events--;
	free_dup_event(oe, event->event);
	event->event = NULL;
	}

	int ordered_events__queue(struct ordered_events oe, union perf_event event,
	u64 timestamp, u64 file_offset)
	{
	struct ordered_event *oevent;

	if (!timestamp \|\| timestamp == ~0ULL)
	return -ETIME;

	if (timestamp < oe->last_flush) {
	pr_oe_time(timestamp, "out of order event\n");
	pr_oe_time(oe->last_flush, "last flush, last_flush_type %d\n",
	oe->last_flush_type);

	oe->nr_unordered_events++;
	}

	oevent = ordered_events__new_event(oe, timestamp, event);
	if (!oevent) {
	ordered_events__flush(oe, OE_FLUSH__HALF);
	oevent = ordered_events__new_event(oe, timestamp, event);
	}

	if (!oevent)
	return -ENOMEM;

	oevent->file_offset = file_offset;
	return 0;
	}

	static int do_flush(struct ordered_events *oe, bool show_progress)
	{
	struct list_head *head = &oe->events;
	struct ordered_event tmp, iter;
	u64 limit = oe->next_flush;
	u64 last_ts = oe->last ? oe->last->timestamp : 0ULL;
	struct ui_progress prog;
	int ret;

	if (!limit)
	return 0;

	if (show_progress)
	ui_progress__init(&prog, oe->nr_events, "Processing time ordered events...");

	list_for_each_entry_safe(iter, tmp, head, list) {
	if (session_done())
	return 0;

	if (iter->timestamp > limit)
	break;
	ret = oe->deliver(oe, iter);
	if (ret)
	return ret;

	ordered_events__delete(oe, iter);
	oe->last_flush = iter->timestamp;

	if (show_progress)
	ui_progress__update(&prog, 1);
	}

	if (list_empty(head))
	oe->last = NULL;
	else if (last_ts <= limit)
	oe->last = list_entry(head->prev, struct ordered_event, list);

	if (show_progress)
	ui_progress__finish();

	return 0;
	}

	static int __ordered_events__flush(struct ordered_events *oe, enum oe_flush how,
	u64 timestamp)
	{
	static const char * const str[] = {
	"NONE",
	"FINAL",
	"ROUND",
	"HALF ",
	};
	int err;
	bool show_progress = false;

	if (oe->nr_events == 0)
	return 0;

	switch (how) {
	case OE_FLUSH__FINAL:
	show_progress = true;
	__fallthrough;
	case OE_FLUSH__TOP:
	oe->next_flush = ULLONG_MAX;
	break;

	case OE_FLUSH__HALF:
	{
	struct ordered_event first, last;
	struct list_head *head = &oe->events;

	first = list_entry(head->next, struct ordered_event, list);
	last = oe->last;

	/* Warn if we are called before any event got allocated. */
	if (WARN_ONCE(!last \|\| list_empty(head), "empty queue"))
	return 0;

	oe->next_flush = first->timestamp;
	oe->next_flush += (last->timestamp - first->timestamp) / 2;
	break;
	}

	case OE_FLUSH__TIME:
	oe->next_flush = timestamp;
	show_progress = false;
	break;

	case OE_FLUSH__ROUND:
	case OE_FLUSH__NONE:
	default:
	break;
	};

	pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush PRE %s, nr_events %u\n",
	str[how], oe->nr_events);
	pr_oe_time(oe->max_timestamp, "max_timestamp\n");

	err = do_flush(oe, show_progress);

	if (!err) {
	if (how == OE_FLUSH__ROUND)
	oe->next_flush = oe->max_timestamp;

	oe->last_flush_type = how;
	}

	pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush POST %s, nr_events %u\n",
	str[how], oe->nr_events);
	pr_oe_time(oe->last_flush, "last_flush\n");

	return err;
	}

	int ordered_events__flush(struct ordered_events *oe, enum oe_flush how)
	{
	return __ordered_events__flush(oe, how, 0);
	}

	int ordered_events__flush_time(struct ordered_events *oe, u64 timestamp)
	{
	return __ordered_events__flush(oe, OE_FLUSH__TIME, timestamp);
	}

	u64 ordered_events__first_time(struct ordered_events *oe)
	{
	struct ordered_event *event;

	if (list_empty(&oe->events))
	return 0;

	event = list_first_entry(&oe->events, struct ordered_event, list);
	return event->timestamp;
	}

	void ordered_events__init(struct ordered_events *oe, ordered_events__deliver_t deliver,
	void *data)
	{
	INIT_LIST_HEAD(&oe->events);
	INIT_LIST_HEAD(&oe->cache);
	INIT_LIST_HEAD(&oe->to_free);
	oe->max_alloc_size = (u64) -1;
	oe->cur_alloc_size = 0;
	oe->deliver = deliver;
	oe->data = data;
	}

	static void
	ordered_events_buffer__free(struct ordered_events_buffer *buffer,
	unsigned int max, struct ordered_events *oe)
	{
	if (oe->copy_on_queue) {
	unsigned int i;

	for (i = 0; i < max; i++)
	__free_dup_event(oe, buffer->event[i].event);
	}

	free(buffer);
	}

	void ordered_events__free(struct ordered_events *oe)
	{
	struct ordered_events_buffer buffer, tmp;

	if (list_empty(&oe->to_free))
	return;

	/*
	* Current buffer might not have all the events allocated
	* yet, we need to free only allocated ones ...
	*/
	list_del(&oe->buffer->list);
	ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe);

	/* ... and continue with the rest */
	list_for_each_entry_safe(buffer, tmp, &oe->to_free, list) {
	list_del(&buffer->list);
	ordered_events_buffer__free(buffer, MAX_SAMPLE_BUFFER, oe);
	}
	}

	void ordered_events__reinit(struct ordered_events *oe)
	{
	ordered_events__deliver_t old_deliver = oe->deliver;

	ordered_events__free(oe);
	memset(oe, '\0', sizeof(*oe));
	ordered_events__init(oe, old_deliver, oe->data);
	}