xref: /openbmc/linux/tools/perf/util/ordered-events.c (revision 8c749ce9)
1 #include <linux/list.h>
2 #include <linux/compiler.h>
3 #include <linux/string.h>
4 #include "ordered-events.h"
5 #include "session.h"
6 #include "asm/bug.h"
7 #include "debug.h"
8 
9 #define pr_N(n, fmt, ...) \
10 	eprintf(n, debug_ordered_events, fmt, ##__VA_ARGS__)
11 
12 #define pr(fmt, ...) pr_N(1, pr_fmt(fmt), ##__VA_ARGS__)
13 
14 static void queue_event(struct ordered_events *oe, struct ordered_event *new)
15 {
16 	struct ordered_event *last = oe->last;
17 	u64 timestamp = new->timestamp;
18 	struct list_head *p;
19 
20 	++oe->nr_events;
21 	oe->last = new;
22 
23 	pr_oe_time2(timestamp, "queue_event nr_events %u\n", oe->nr_events);
24 
25 	if (!last) {
26 		list_add(&new->list, &oe->events);
27 		oe->max_timestamp = timestamp;
28 		return;
29 	}
30 
31 	/*
32 	 * last event might point to some random place in the list as it's
33 	 * the last queued event. We expect that the new event is close to
34 	 * this.
35 	 */
36 	if (last->timestamp <= timestamp) {
37 		while (last->timestamp <= timestamp) {
38 			p = last->list.next;
39 			if (p == &oe->events) {
40 				list_add_tail(&new->list, &oe->events);
41 				oe->max_timestamp = timestamp;
42 				return;
43 			}
44 			last = list_entry(p, struct ordered_event, list);
45 		}
46 		list_add_tail(&new->list, &last->list);
47 	} else {
48 		while (last->timestamp > timestamp) {
49 			p = last->list.prev;
50 			if (p == &oe->events) {
51 				list_add(&new->list, &oe->events);
52 				return;
53 			}
54 			last = list_entry(p, struct ordered_event, list);
55 		}
56 		list_add(&new->list, &last->list);
57 	}
58 }
59 
60 static union perf_event *__dup_event(struct ordered_events *oe,
61 				     union perf_event *event)
62 {
63 	union perf_event *new_event = NULL;
64 
65 	if (oe->cur_alloc_size < oe->max_alloc_size) {
66 		new_event = memdup(event, event->header.size);
67 		if (new_event)
68 			oe->cur_alloc_size += event->header.size;
69 	}
70 
71 	return new_event;
72 }
73 
74 static union perf_event *dup_event(struct ordered_events *oe,
75 				   union perf_event *event)
76 {
77 	return oe->copy_on_queue ? __dup_event(oe, event) : event;
78 }
79 
80 static void free_dup_event(struct ordered_events *oe, union perf_event *event)
81 {
82 	if (oe->copy_on_queue) {
83 		oe->cur_alloc_size -= event->header.size;
84 		free(event);
85 	}
86 }
87 
88 #define MAX_SAMPLE_BUFFER	(64 * 1024 / sizeof(struct ordered_event))
89 static struct ordered_event *alloc_event(struct ordered_events *oe,
90 					 union perf_event *event)
91 {
92 	struct list_head *cache = &oe->cache;
93 	struct ordered_event *new = NULL;
94 	union perf_event *new_event;
95 
96 	new_event = dup_event(oe, event);
97 	if (!new_event)
98 		return NULL;
99 
100 	if (!list_empty(cache)) {
101 		new = list_entry(cache->next, struct ordered_event, list);
102 		list_del(&new->list);
103 	} else if (oe->buffer) {
104 		new = oe->buffer + oe->buffer_idx;
105 		if (++oe->buffer_idx == MAX_SAMPLE_BUFFER)
106 			oe->buffer = NULL;
107 	} else if (oe->cur_alloc_size < oe->max_alloc_size) {
108 		size_t size = MAX_SAMPLE_BUFFER * sizeof(*new);
109 
110 		oe->buffer = malloc(size);
111 		if (!oe->buffer) {
112 			free_dup_event(oe, new_event);
113 			return NULL;
114 		}
115 
116 		pr("alloc size %" PRIu64 "B (+%zu), max %" PRIu64 "B\n",
117 		   oe->cur_alloc_size, size, oe->max_alloc_size);
118 
119 		oe->cur_alloc_size += size;
120 		list_add(&oe->buffer->list, &oe->to_free);
121 
122 		/* First entry is abused to maintain the to_free list. */
123 		oe->buffer_idx = 2;
124 		new = oe->buffer + 1;
125 	} else {
126 		pr("allocation limit reached %" PRIu64 "B\n", oe->max_alloc_size);
127 	}
128 
129 	new->event = new_event;
130 	return new;
131 }
132 
133 static struct ordered_event *
134 ordered_events__new_event(struct ordered_events *oe, u64 timestamp,
135 		    union perf_event *event)
136 {
137 	struct ordered_event *new;
138 
139 	new = alloc_event(oe, event);
140 	if (new) {
141 		new->timestamp = timestamp;
142 		queue_event(oe, new);
143 	}
144 
145 	return new;
146 }
147 
148 void ordered_events__delete(struct ordered_events *oe, struct ordered_event *event)
149 {
150 	list_move(&event->list, &oe->cache);
151 	oe->nr_events--;
152 	free_dup_event(oe, event->event);
153 }
154 
155 int ordered_events__queue(struct ordered_events *oe, union perf_event *event,
156 			  struct perf_sample *sample, u64 file_offset)
157 {
158 	u64 timestamp = sample->time;
159 	struct ordered_event *oevent;
160 
161 	if (!timestamp || timestamp == ~0ULL)
162 		return -ETIME;
163 
164 	if (timestamp < oe->last_flush) {
165 		pr_oe_time(timestamp,      "out of order event\n");
166 		pr_oe_time(oe->last_flush, "last flush, last_flush_type %d\n",
167 			   oe->last_flush_type);
168 
169 		oe->nr_unordered_events++;
170 	}
171 
172 	oevent = ordered_events__new_event(oe, timestamp, event);
173 	if (!oevent) {
174 		ordered_events__flush(oe, OE_FLUSH__HALF);
175 		oevent = ordered_events__new_event(oe, timestamp, event);
176 	}
177 
178 	if (!oevent)
179 		return -ENOMEM;
180 
181 	oevent->file_offset = file_offset;
182 	return 0;
183 }
184 
185 static int __ordered_events__flush(struct ordered_events *oe)
186 {
187 	struct list_head *head = &oe->events;
188 	struct ordered_event *tmp, *iter;
189 	u64 limit = oe->next_flush;
190 	u64 last_ts = oe->last ? oe->last->timestamp : 0ULL;
191 	bool show_progress = limit == ULLONG_MAX;
192 	struct ui_progress prog;
193 	int ret;
194 
195 	if (!limit)
196 		return 0;
197 
198 	if (show_progress)
199 		ui_progress__init(&prog, oe->nr_events, "Processing time ordered events...");
200 
201 	list_for_each_entry_safe(iter, tmp, head, list) {
202 		if (session_done())
203 			return 0;
204 
205 		if (iter->timestamp > limit)
206 			break;
207 		ret = oe->deliver(oe, iter);
208 		if (ret)
209 			return ret;
210 
211 		ordered_events__delete(oe, iter);
212 		oe->last_flush = iter->timestamp;
213 
214 		if (show_progress)
215 			ui_progress__update(&prog, 1);
216 	}
217 
218 	if (list_empty(head))
219 		oe->last = NULL;
220 	else if (last_ts <= limit)
221 		oe->last = list_entry(head->prev, struct ordered_event, list);
222 
223 	if (show_progress)
224 		ui_progress__finish();
225 
226 	return 0;
227 }
228 
229 int ordered_events__flush(struct ordered_events *oe, enum oe_flush how)
230 {
231 	static const char * const str[] = {
232 		"NONE",
233 		"FINAL",
234 		"ROUND",
235 		"HALF ",
236 	};
237 	int err;
238 
239 	if (oe->nr_events == 0)
240 		return 0;
241 
242 	switch (how) {
243 	case OE_FLUSH__FINAL:
244 		oe->next_flush = ULLONG_MAX;
245 		break;
246 
247 	case OE_FLUSH__HALF:
248 	{
249 		struct ordered_event *first, *last;
250 		struct list_head *head = &oe->events;
251 
252 		first = list_entry(head->next, struct ordered_event, list);
253 		last = oe->last;
254 
255 		/* Warn if we are called before any event got allocated. */
256 		if (WARN_ONCE(!last || list_empty(head), "empty queue"))
257 			return 0;
258 
259 		oe->next_flush  = first->timestamp;
260 		oe->next_flush += (last->timestamp - first->timestamp) / 2;
261 		break;
262 	}
263 
264 	case OE_FLUSH__ROUND:
265 	case OE_FLUSH__NONE:
266 	default:
267 		break;
268 	};
269 
270 	pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush PRE  %s, nr_events %u\n",
271 		   str[how], oe->nr_events);
272 	pr_oe_time(oe->max_timestamp, "max_timestamp\n");
273 
274 	err = __ordered_events__flush(oe);
275 
276 	if (!err) {
277 		if (how == OE_FLUSH__ROUND)
278 			oe->next_flush = oe->max_timestamp;
279 
280 		oe->last_flush_type = how;
281 	}
282 
283 	pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush POST %s, nr_events %u\n",
284 		   str[how], oe->nr_events);
285 	pr_oe_time(oe->last_flush, "last_flush\n");
286 
287 	return err;
288 }
289 
290 void ordered_events__init(struct ordered_events *oe, ordered_events__deliver_t deliver)
291 {
292 	INIT_LIST_HEAD(&oe->events);
293 	INIT_LIST_HEAD(&oe->cache);
294 	INIT_LIST_HEAD(&oe->to_free);
295 	oe->max_alloc_size = (u64) -1;
296 	oe->cur_alloc_size = 0;
297 	oe->deliver	   = deliver;
298 }
299 
300 void ordered_events__free(struct ordered_events *oe)
301 {
302 	while (!list_empty(&oe->to_free)) {
303 		struct ordered_event *event;
304 
305 		event = list_entry(oe->to_free.next, struct ordered_event, list);
306 		list_del(&event->list);
307 		free_dup_event(oe, event->event);
308 		free(event);
309 	}
310 }
311