summaryrefslogtreecommitdiffstats
path: root/kernel/tools/perf/util/ordered-events.c
blob: 52be201b9b2559ffde22a0b81d7b6767bef37173 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
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);
	}
}