xref: /openbmc/linux/tools/perf/util/stat.c (revision 9cfc5c90)
1 #include <math.h>
2 #include "stat.h"
3 #include "evlist.h"
4 #include "evsel.h"
5 #include "thread_map.h"
6 
7 void update_stats(struct stats *stats, u64 val)
8 {
9 	double delta;
10 
11 	stats->n++;
12 	delta = val - stats->mean;
13 	stats->mean += delta / stats->n;
14 	stats->M2 += delta*(val - stats->mean);
15 
16 	if (val > stats->max)
17 		stats->max = val;
18 
19 	if (val < stats->min)
20 		stats->min = val;
21 }
22 
23 double avg_stats(struct stats *stats)
24 {
25 	return stats->mean;
26 }
27 
28 /*
29  * http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
30  *
31  *       (\Sum n_i^2) - ((\Sum n_i)^2)/n
32  * s^2 = -------------------------------
33  *                  n - 1
34  *
35  * http://en.wikipedia.org/wiki/Stddev
36  *
37  * The std dev of the mean is related to the std dev by:
38  *
39  *             s
40  * s_mean = -------
41  *          sqrt(n)
42  *
43  */
44 double stddev_stats(struct stats *stats)
45 {
46 	double variance, variance_mean;
47 
48 	if (stats->n < 2)
49 		return 0.0;
50 
51 	variance = stats->M2 / (stats->n - 1);
52 	variance_mean = variance / stats->n;
53 
54 	return sqrt(variance_mean);
55 }
56 
57 double rel_stddev_stats(double stddev, double avg)
58 {
59 	double pct = 0.0;
60 
61 	if (avg)
62 		pct = 100.0 * stddev/avg;
63 
64 	return pct;
65 }
66 
67 bool __perf_evsel_stat__is(struct perf_evsel *evsel,
68 			   enum perf_stat_evsel_id id)
69 {
70 	struct perf_stat_evsel *ps = evsel->priv;
71 
72 	return ps->id == id;
73 }
74 
75 #define ID(id, name) [PERF_STAT_EVSEL_ID__##id] = #name
76 static const char *id_str[PERF_STAT_EVSEL_ID__MAX] = {
77 	ID(NONE,		x),
78 	ID(CYCLES_IN_TX,	cpu/cycles-t/),
79 	ID(TRANSACTION_START,	cpu/tx-start/),
80 	ID(ELISION_START,	cpu/el-start/),
81 	ID(CYCLES_IN_TX_CP,	cpu/cycles-ct/),
82 };
83 #undef ID
84 
85 void perf_stat_evsel_id_init(struct perf_evsel *evsel)
86 {
87 	struct perf_stat_evsel *ps = evsel->priv;
88 	int i;
89 
90 	/* ps->id is 0 hence PERF_STAT_EVSEL_ID__NONE by default */
91 
92 	for (i = 0; i < PERF_STAT_EVSEL_ID__MAX; i++) {
93 		if (!strcmp(perf_evsel__name(evsel), id_str[i])) {
94 			ps->id = i;
95 			break;
96 		}
97 	}
98 }
99 
100 void perf_evsel__reset_stat_priv(struct perf_evsel *evsel)
101 {
102 	int i;
103 	struct perf_stat_evsel *ps = evsel->priv;
104 
105 	for (i = 0; i < 3; i++)
106 		init_stats(&ps->res_stats[i]);
107 
108 	perf_stat_evsel_id_init(evsel);
109 }
110 
111 int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel)
112 {
113 	evsel->priv = zalloc(sizeof(struct perf_stat_evsel));
114 	if (evsel->priv == NULL)
115 		return -ENOMEM;
116 	perf_evsel__reset_stat_priv(evsel);
117 	return 0;
118 }
119 
120 void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
121 {
122 	zfree(&evsel->priv);
123 }
124 
125 int perf_evsel__alloc_prev_raw_counts(struct perf_evsel *evsel,
126 				      int ncpus, int nthreads)
127 {
128 	struct perf_counts *counts;
129 
130 	counts = perf_counts__new(ncpus, nthreads);
131 	if (counts)
132 		evsel->prev_raw_counts = counts;
133 
134 	return counts ? 0 : -ENOMEM;
135 }
136 
137 void perf_evsel__free_prev_raw_counts(struct perf_evsel *evsel)
138 {
139 	perf_counts__delete(evsel->prev_raw_counts);
140 	evsel->prev_raw_counts = NULL;
141 }
142 
143 int perf_evsel__alloc_stats(struct perf_evsel *evsel, bool alloc_raw)
144 {
145 	int ncpus = perf_evsel__nr_cpus(evsel);
146 	int nthreads = thread_map__nr(evsel->threads);
147 
148 	if (perf_evsel__alloc_stat_priv(evsel) < 0 ||
149 	    perf_evsel__alloc_counts(evsel, ncpus, nthreads) < 0 ||
150 	    (alloc_raw && perf_evsel__alloc_prev_raw_counts(evsel, ncpus, nthreads) < 0))
151 		return -ENOMEM;
152 
153 	return 0;
154 }
155 
156 int perf_evlist__alloc_stats(struct perf_evlist *evlist, bool alloc_raw)
157 {
158 	struct perf_evsel *evsel;
159 
160 	evlist__for_each(evlist, evsel) {
161 		if (perf_evsel__alloc_stats(evsel, alloc_raw))
162 			goto out_free;
163 	}
164 
165 	return 0;
166 
167 out_free:
168 	perf_evlist__free_stats(evlist);
169 	return -1;
170 }
171 
172 void perf_evlist__free_stats(struct perf_evlist *evlist)
173 {
174 	struct perf_evsel *evsel;
175 
176 	evlist__for_each(evlist, evsel) {
177 		perf_evsel__free_stat_priv(evsel);
178 		perf_evsel__free_counts(evsel);
179 		perf_evsel__free_prev_raw_counts(evsel);
180 	}
181 }
182 
183 void perf_evlist__reset_stats(struct perf_evlist *evlist)
184 {
185 	struct perf_evsel *evsel;
186 
187 	evlist__for_each(evlist, evsel) {
188 		perf_evsel__reset_stat_priv(evsel);
189 		perf_evsel__reset_counts(evsel);
190 	}
191 }
192 
193 static void zero_per_pkg(struct perf_evsel *counter)
194 {
195 	if (counter->per_pkg_mask)
196 		memset(counter->per_pkg_mask, 0, MAX_NR_CPUS);
197 }
198 
199 static int check_per_pkg(struct perf_evsel *counter,
200 			 struct perf_counts_values *vals, int cpu, bool *skip)
201 {
202 	unsigned long *mask = counter->per_pkg_mask;
203 	struct cpu_map *cpus = perf_evsel__cpus(counter);
204 	int s;
205 
206 	*skip = false;
207 
208 	if (!counter->per_pkg)
209 		return 0;
210 
211 	if (cpu_map__empty(cpus))
212 		return 0;
213 
214 	if (!mask) {
215 		mask = zalloc(MAX_NR_CPUS);
216 		if (!mask)
217 			return -ENOMEM;
218 
219 		counter->per_pkg_mask = mask;
220 	}
221 
222 	/*
223 	 * we do not consider an event that has not run as a good
224 	 * instance to mark a package as used (skip=1). Otherwise
225 	 * we may run into a situation where the first CPU in a package
226 	 * is not running anything, yet the second is, and this function
227 	 * would mark the package as used after the first CPU and would
228 	 * not read the values from the second CPU.
229 	 */
230 	if (!(vals->run && vals->ena))
231 		return 0;
232 
233 	s = cpu_map__get_socket(cpus, cpu, NULL);
234 	if (s < 0)
235 		return -1;
236 
237 	*skip = test_and_set_bit(s, mask) == 1;
238 	return 0;
239 }
240 
241 static int
242 process_counter_values(struct perf_stat_config *config, struct perf_evsel *evsel,
243 		       int cpu, int thread,
244 		       struct perf_counts_values *count)
245 {
246 	struct perf_counts_values *aggr = &evsel->counts->aggr;
247 	static struct perf_counts_values zero;
248 	bool skip = false;
249 
250 	if (check_per_pkg(evsel, count, cpu, &skip)) {
251 		pr_err("failed to read per-pkg counter\n");
252 		return -1;
253 	}
254 
255 	if (skip)
256 		count = &zero;
257 
258 	switch (config->aggr_mode) {
259 	case AGGR_THREAD:
260 	case AGGR_CORE:
261 	case AGGR_SOCKET:
262 	case AGGR_NONE:
263 		if (!evsel->snapshot)
264 			perf_evsel__compute_deltas(evsel, cpu, thread, count);
265 		perf_counts_values__scale(count, config->scale, NULL);
266 		if (config->aggr_mode == AGGR_NONE)
267 			perf_stat__update_shadow_stats(evsel, count->values, cpu);
268 		break;
269 	case AGGR_GLOBAL:
270 		aggr->val += count->val;
271 		if (config->scale) {
272 			aggr->ena += count->ena;
273 			aggr->run += count->run;
274 		}
275 	case AGGR_UNSET:
276 	default:
277 		break;
278 	}
279 
280 	return 0;
281 }
282 
283 static int process_counter_maps(struct perf_stat_config *config,
284 				struct perf_evsel *counter)
285 {
286 	int nthreads = thread_map__nr(counter->threads);
287 	int ncpus = perf_evsel__nr_cpus(counter);
288 	int cpu, thread;
289 
290 	if (counter->system_wide)
291 		nthreads = 1;
292 
293 	for (thread = 0; thread < nthreads; thread++) {
294 		for (cpu = 0; cpu < ncpus; cpu++) {
295 			if (process_counter_values(config, counter, cpu, thread,
296 						   perf_counts(counter->counts, cpu, thread)))
297 				return -1;
298 		}
299 	}
300 
301 	return 0;
302 }
303 
304 int perf_stat_process_counter(struct perf_stat_config *config,
305 			      struct perf_evsel *counter)
306 {
307 	struct perf_counts_values *aggr = &counter->counts->aggr;
308 	struct perf_stat_evsel *ps = counter->priv;
309 	u64 *count = counter->counts->aggr.values;
310 	int i, ret;
311 
312 	aggr->val = aggr->ena = aggr->run = 0;
313 	init_stats(ps->res_stats);
314 
315 	if (counter->per_pkg)
316 		zero_per_pkg(counter);
317 
318 	ret = process_counter_maps(config, counter);
319 	if (ret)
320 		return ret;
321 
322 	if (config->aggr_mode != AGGR_GLOBAL)
323 		return 0;
324 
325 	if (!counter->snapshot)
326 		perf_evsel__compute_deltas(counter, -1, -1, aggr);
327 	perf_counts_values__scale(aggr, config->scale, &counter->counts->scaled);
328 
329 	for (i = 0; i < 3; i++)
330 		update_stats(&ps->res_stats[i], count[i]);
331 
332 	if (verbose) {
333 		fprintf(config->output, "%s: %" PRIu64 " %" PRIu64 " %" PRIu64 "\n",
334 			perf_evsel__name(counter), count[0], count[1], count[2]);
335 	}
336 
337 	/*
338 	 * Save the full runtime - to allow normalization during printout:
339 	 */
340 	perf_stat__update_shadow_stats(counter, count, 0);
341 
342 	return 0;
343 }
344