1 files changed, 307 insertions, 0 deletions

diff --git a/kernel/tools/perf/util/ordered-events.c b/kernel/tools/perf/util/ordered-events.c
new file mode 100644
index 000000000..52be201b9
--- /dev/null
+++ b/kernel/tools/perf/util/ordered-events.c
@@ -0,0 +1,307 @@
+#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 (oe->copy_on_queue) {
+		oe->cur_alloc_size -= event->header.size;
+		free(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;
+
+	new_event = dup_event(oe, event);
+	if (!new_event)
+		return NULL;
+
+	if (!list_empty(cache)) {
+		new = list_entry(cache->next, struct ordered_event, list);
+		list_del(&new->list);
+	} else if (oe->buffer) {
+		new = oe->buffer + oe->buffer_idx;
+		if (++oe->buffer_idx == MAX_SAMPLE_BUFFER)
+			oe->buffer = NULL;
+	} else if (oe->cur_alloc_size < oe->max_alloc_size) {
+		size_t size = MAX_SAMPLE_BUFFER * sizeof(*new);
+
+		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);
+
+		/* First entry is abused to maintain the to_free list. */
+		oe->buffer_idx = 2;
+		new = oe->buffer + 1;
+	} else {
+		pr("allocation limit reached %" PRIu64 "B\n", oe->max_alloc_size);
+	}
+
+	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);
+}
+
+int ordered_events__queue(struct ordered_events *oe, union perf_event *event,
+			  struct perf_sample *sample, u64 file_offset)
+{
+	u64 timestamp = sample->time;
+	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 __ordered_events__flush(struct ordered_events *oe)
+{
+	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;
+	bool show_progress = limit == ULLONG_MAX;
+	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);
+
+	return 0;
+}
+
+int ordered_events__flush(struct ordered_events *oe, enum oe_flush how)
+{
+	static const char * const str[] = {
+		"NONE",
+		"FINAL",
+		"ROUND",
+		"HALF ",
+	};
+	int err;
+
+	if (oe->nr_events == 0)
+		return 0;
+
+	switch (how) {
+	case OE_FLUSH__FINAL:
+		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__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 = __ordered_events__flush(oe);
+
+	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;
+}
+
+void ordered_events__init(struct ordered_events *oe, ordered_events__deliver_t deliver)
+{
+	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;
+}
+
+void ordered_events__free(struct ordered_events *oe)
+{
+	while (!list_empty(&oe->to_free)) {
+		struct ordered_event *event;
+
+		event = list_entry(oe->to_free.next, struct ordered_event, list);
+		list_del(&event->list);
+		free_dup_event(oe, event->event);
+		free(event);
+	}
+}