xref: /linux/tools/perf/util/evsel.c (revision a91e5431d54f5359fccb5ec2512f252eb217707e)
1 /*
2  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
3  *
4  * Parts came from builtin-{top,stat,record}.c, see those files for further
5  * copyright notes.
6  *
7  * Released under the GPL v2. (and only v2, not any later version)
8  */
9 
10 #include "evsel.h"
11 #include "evlist.h"
12 #include "util.h"
13 #include "cpumap.h"
14 #include "thread_map.h"
15 
16 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
17 
18 void perf_evsel__init(struct perf_evsel *evsel,
19 		      struct perf_event_attr *attr, int idx)
20 {
21 	evsel->idx	   = idx;
22 	evsel->attr	   = *attr;
23 	INIT_LIST_HEAD(&evsel->node);
24 }
25 
26 struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx)
27 {
28 	struct perf_evsel *evsel = zalloc(sizeof(*evsel));
29 
30 	if (evsel != NULL)
31 		perf_evsel__init(evsel, attr, idx);
32 
33 	return evsel;
34 }
35 
36 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
37 {
38 	evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
39 	return evsel->fd != NULL ? 0 : -ENOMEM;
40 }
41 
42 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
43 {
44 	evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
45 	if (evsel->sample_id == NULL)
46 		return -ENOMEM;
47 
48 	evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
49 	if (evsel->id == NULL) {
50 		xyarray__delete(evsel->sample_id);
51 		evsel->sample_id = NULL;
52 		return -ENOMEM;
53 	}
54 
55 	return 0;
56 }
57 
58 int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus)
59 {
60 	evsel->counts = zalloc((sizeof(*evsel->counts) +
61 				(ncpus * sizeof(struct perf_counts_values))));
62 	return evsel->counts != NULL ? 0 : -ENOMEM;
63 }
64 
65 void perf_evsel__free_fd(struct perf_evsel *evsel)
66 {
67 	xyarray__delete(evsel->fd);
68 	evsel->fd = NULL;
69 }
70 
71 void perf_evsel__free_id(struct perf_evsel *evsel)
72 {
73 	xyarray__delete(evsel->sample_id);
74 	evsel->sample_id = NULL;
75 	free(evsel->id);
76 	evsel->id = NULL;
77 }
78 
79 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
80 {
81 	int cpu, thread;
82 
83 	for (cpu = 0; cpu < ncpus; cpu++)
84 		for (thread = 0; thread < nthreads; ++thread) {
85 			close(FD(evsel, cpu, thread));
86 			FD(evsel, cpu, thread) = -1;
87 		}
88 }
89 
90 void perf_evsel__exit(struct perf_evsel *evsel)
91 {
92 	assert(list_empty(&evsel->node));
93 	xyarray__delete(evsel->fd);
94 	xyarray__delete(evsel->sample_id);
95 	free(evsel->id);
96 }
97 
98 void perf_evsel__delete(struct perf_evsel *evsel)
99 {
100 	perf_evsel__exit(evsel);
101 	close_cgroup(evsel->cgrp);
102 	free(evsel->name);
103 	free(evsel);
104 }
105 
106 int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
107 			      int cpu, int thread, bool scale)
108 {
109 	struct perf_counts_values count;
110 	size_t nv = scale ? 3 : 1;
111 
112 	if (FD(evsel, cpu, thread) < 0)
113 		return -EINVAL;
114 
115 	if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1) < 0)
116 		return -ENOMEM;
117 
118 	if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0)
119 		return -errno;
120 
121 	if (scale) {
122 		if (count.run == 0)
123 			count.val = 0;
124 		else if (count.run < count.ena)
125 			count.val = (u64)((double)count.val * count.ena / count.run + 0.5);
126 	} else
127 		count.ena = count.run = 0;
128 
129 	evsel->counts->cpu[cpu] = count;
130 	return 0;
131 }
132 
133 int __perf_evsel__read(struct perf_evsel *evsel,
134 		       int ncpus, int nthreads, bool scale)
135 {
136 	size_t nv = scale ? 3 : 1;
137 	int cpu, thread;
138 	struct perf_counts_values *aggr = &evsel->counts->aggr, count;
139 
140 	aggr->val = aggr->ena = aggr->run = 0;
141 
142 	for (cpu = 0; cpu < ncpus; cpu++) {
143 		for (thread = 0; thread < nthreads; thread++) {
144 			if (FD(evsel, cpu, thread) < 0)
145 				continue;
146 
147 			if (readn(FD(evsel, cpu, thread),
148 				  &count, nv * sizeof(u64)) < 0)
149 				return -errno;
150 
151 			aggr->val += count.val;
152 			if (scale) {
153 				aggr->ena += count.ena;
154 				aggr->run += count.run;
155 			}
156 		}
157 	}
158 
159 	evsel->counts->scaled = 0;
160 	if (scale) {
161 		if (aggr->run == 0) {
162 			evsel->counts->scaled = -1;
163 			aggr->val = 0;
164 			return 0;
165 		}
166 
167 		if (aggr->run < aggr->ena) {
168 			evsel->counts->scaled = 1;
169 			aggr->val = (u64)((double)aggr->val * aggr->ena / aggr->run + 0.5);
170 		}
171 	} else
172 		aggr->ena = aggr->run = 0;
173 
174 	return 0;
175 }
176 
177 static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
178 			      struct thread_map *threads, bool group, bool inherit)
179 {
180 	int cpu, thread;
181 	unsigned long flags = 0;
182 	int pid = -1;
183 
184 	if (evsel->fd == NULL &&
185 	    perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0)
186 		return -1;
187 
188 	if (evsel->cgrp) {
189 		flags = PERF_FLAG_PID_CGROUP;
190 		pid = evsel->cgrp->fd;
191 	}
192 
193 	for (cpu = 0; cpu < cpus->nr; cpu++) {
194 		int group_fd = -1;
195 		/*
196 		 * Don't allow mmap() of inherited per-task counters. This
197 		 * would create a performance issue due to all children writing
198 		 * to the same buffer.
199 		 *
200 		 * FIXME:
201 		 * Proper fix is not to pass 'inherit' to perf_evsel__open*,
202 		 * but a 'flags' parameter, with 'group' folded there as well,
203 		 * then introduce a PERF_O_{MMAP,GROUP,INHERIT} enum, and if
204 		 * O_MMAP is set, emit a warning if cpu < 0 and O_INHERIT is
205 		 * set. Lets go for the minimal fix first tho.
206 		 */
207 		evsel->attr.inherit = (cpus->map[cpu] >= 0) && inherit;
208 
209 		for (thread = 0; thread < threads->nr; thread++) {
210 
211 			if (!evsel->cgrp)
212 				pid = threads->map[thread];
213 
214 			FD(evsel, cpu, thread) = sys_perf_event_open(&evsel->attr,
215 								     pid,
216 								     cpus->map[cpu],
217 								     group_fd, flags);
218 			if (FD(evsel, cpu, thread) < 0)
219 				goto out_close;
220 
221 			if (group && group_fd == -1)
222 				group_fd = FD(evsel, cpu, thread);
223 		}
224 	}
225 
226 	return 0;
227 
228 out_close:
229 	do {
230 		while (--thread >= 0) {
231 			close(FD(evsel, cpu, thread));
232 			FD(evsel, cpu, thread) = -1;
233 		}
234 		thread = threads->nr;
235 	} while (--cpu >= 0);
236 	return -1;
237 }
238 
239 static struct {
240 	struct cpu_map map;
241 	int cpus[1];
242 } empty_cpu_map = {
243 	.map.nr	= 1,
244 	.cpus	= { -1, },
245 };
246 
247 static struct {
248 	struct thread_map map;
249 	int threads[1];
250 } empty_thread_map = {
251 	.map.nr	 = 1,
252 	.threads = { -1, },
253 };
254 
255 int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
256 		     struct thread_map *threads, bool group, bool inherit)
257 {
258 	if (cpus == NULL) {
259 		/* Work around old compiler warnings about strict aliasing */
260 		cpus = &empty_cpu_map.map;
261 	}
262 
263 	if (threads == NULL)
264 		threads = &empty_thread_map.map;
265 
266 	return __perf_evsel__open(evsel, cpus, threads, group, inherit);
267 }
268 
269 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
270 			     struct cpu_map *cpus, bool group, bool inherit)
271 {
272 	return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group, inherit);
273 }
274 
275 int perf_evsel__open_per_thread(struct perf_evsel *evsel,
276 				struct thread_map *threads, bool group, bool inherit)
277 {
278 	return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group, inherit);
279 }
280 
281 static int perf_event__parse_id_sample(const union perf_event *event, u64 type,
282 				       struct perf_sample *sample)
283 {
284 	const u64 *array = event->sample.array;
285 
286 	array += ((event->header.size -
287 		   sizeof(event->header)) / sizeof(u64)) - 1;
288 
289 	if (type & PERF_SAMPLE_CPU) {
290 		u32 *p = (u32 *)array;
291 		sample->cpu = *p;
292 		array--;
293 	}
294 
295 	if (type & PERF_SAMPLE_STREAM_ID) {
296 		sample->stream_id = *array;
297 		array--;
298 	}
299 
300 	if (type & PERF_SAMPLE_ID) {
301 		sample->id = *array;
302 		array--;
303 	}
304 
305 	if (type & PERF_SAMPLE_TIME) {
306 		sample->time = *array;
307 		array--;
308 	}
309 
310 	if (type & PERF_SAMPLE_TID) {
311 		u32 *p = (u32 *)array;
312 		sample->pid = p[0];
313 		sample->tid = p[1];
314 	}
315 
316 	return 0;
317 }
318 
319 int perf_event__parse_sample(const union perf_event *event, u64 type,
320 			     bool sample_id_all, struct perf_sample *data)
321 {
322 	const u64 *array;
323 
324 	data->cpu = data->pid = data->tid = -1;
325 	data->stream_id = data->id = data->time = -1ULL;
326 
327 	if (event->header.type != PERF_RECORD_SAMPLE) {
328 		if (!sample_id_all)
329 			return 0;
330 		return perf_event__parse_id_sample(event, type, data);
331 	}
332 
333 	array = event->sample.array;
334 
335 	if (type & PERF_SAMPLE_IP) {
336 		data->ip = event->ip.ip;
337 		array++;
338 	}
339 
340 	if (type & PERF_SAMPLE_TID) {
341 		u32 *p = (u32 *)array;
342 		data->pid = p[0];
343 		data->tid = p[1];
344 		array++;
345 	}
346 
347 	if (type & PERF_SAMPLE_TIME) {
348 		data->time = *array;
349 		array++;
350 	}
351 
352 	if (type & PERF_SAMPLE_ADDR) {
353 		data->addr = *array;
354 		array++;
355 	}
356 
357 	data->id = -1ULL;
358 	if (type & PERF_SAMPLE_ID) {
359 		data->id = *array;
360 		array++;
361 	}
362 
363 	if (type & PERF_SAMPLE_STREAM_ID) {
364 		data->stream_id = *array;
365 		array++;
366 	}
367 
368 	if (type & PERF_SAMPLE_CPU) {
369 		u32 *p = (u32 *)array;
370 		data->cpu = *p;
371 		array++;
372 	}
373 
374 	if (type & PERF_SAMPLE_PERIOD) {
375 		data->period = *array;
376 		array++;
377 	}
378 
379 	if (type & PERF_SAMPLE_READ) {
380 		fprintf(stderr, "PERF_SAMPLE_READ is unsuported for now\n");
381 		return -1;
382 	}
383 
384 	if (type & PERF_SAMPLE_CALLCHAIN) {
385 		data->callchain = (struct ip_callchain *)array;
386 		array += 1 + data->callchain->nr;
387 	}
388 
389 	if (type & PERF_SAMPLE_RAW) {
390 		u32 *p = (u32 *)array;
391 		data->raw_size = *p;
392 		p++;
393 		data->raw_data = p;
394 	}
395 
396 	return 0;
397 }
398