xref: /openbmc/linux/tools/perf/util/stat.c (revision 8b235f2f)
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 *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 *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 *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));
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, int cpu, bool *skip)
200 {
201 	unsigned long *mask = counter->per_pkg_mask;
202 	struct cpu_map *cpus = perf_evsel__cpus(counter);
203 	int s;
204 
205 	*skip = false;
206 
207 	if (!counter->per_pkg)
208 		return 0;
209 
210 	if (cpu_map__empty(cpus))
211 		return 0;
212 
213 	if (!mask) {
214 		mask = zalloc(MAX_NR_CPUS);
215 		if (!mask)
216 			return -ENOMEM;
217 
218 		counter->per_pkg_mask = mask;
219 	}
220 
221 	s = cpu_map__get_socket(cpus, cpu);
222 	if (s < 0)
223 		return -1;
224 
225 	*skip = test_and_set_bit(s, mask) == 1;
226 	return 0;
227 }
228 
229 static int
230 process_counter_values(struct perf_stat_config *config, struct perf_evsel *evsel,
231 		       int cpu, int thread,
232 		       struct perf_counts_values *count)
233 {
234 	struct perf_counts_values *aggr = &evsel->counts->aggr;
235 	static struct perf_counts_values zero;
236 	bool skip = false;
237 
238 	if (check_per_pkg(evsel, cpu, &skip)) {
239 		pr_err("failed to read per-pkg counter\n");
240 		return -1;
241 	}
242 
243 	if (skip)
244 		count = &zero;
245 
246 	switch (config->aggr_mode) {
247 	case AGGR_THREAD:
248 	case AGGR_CORE:
249 	case AGGR_SOCKET:
250 	case AGGR_NONE:
251 		if (!evsel->snapshot)
252 			perf_evsel__compute_deltas(evsel, cpu, thread, count);
253 		perf_counts_values__scale(count, config->scale, NULL);
254 		if (config->aggr_mode == AGGR_NONE)
255 			perf_stat__update_shadow_stats(evsel, count->values, cpu);
256 		break;
257 	case AGGR_GLOBAL:
258 		aggr->val += count->val;
259 		if (config->scale) {
260 			aggr->ena += count->ena;
261 			aggr->run += count->run;
262 		}
263 	default:
264 		break;
265 	}
266 
267 	return 0;
268 }
269 
270 static int process_counter_maps(struct perf_stat_config *config,
271 				struct perf_evsel *counter)
272 {
273 	int nthreads = thread_map__nr(counter->threads);
274 	int ncpus = perf_evsel__nr_cpus(counter);
275 	int cpu, thread;
276 
277 	if (counter->system_wide)
278 		nthreads = 1;
279 
280 	for (thread = 0; thread < nthreads; thread++) {
281 		for (cpu = 0; cpu < ncpus; cpu++) {
282 			if (process_counter_values(config, counter, cpu, thread,
283 						   perf_counts(counter->counts, cpu, thread)))
284 				return -1;
285 		}
286 	}
287 
288 	return 0;
289 }
290 
291 int perf_stat_process_counter(struct perf_stat_config *config,
292 			      struct perf_evsel *counter)
293 {
294 	struct perf_counts_values *aggr = &counter->counts->aggr;
295 	struct perf_stat *ps = counter->priv;
296 	u64 *count = counter->counts->aggr.values;
297 	int i, ret;
298 
299 	aggr->val = aggr->ena = aggr->run = 0;
300 	init_stats(ps->res_stats);
301 
302 	if (counter->per_pkg)
303 		zero_per_pkg(counter);
304 
305 	ret = process_counter_maps(config, counter);
306 	if (ret)
307 		return ret;
308 
309 	if (config->aggr_mode != AGGR_GLOBAL)
310 		return 0;
311 
312 	if (!counter->snapshot)
313 		perf_evsel__compute_deltas(counter, -1, -1, aggr);
314 	perf_counts_values__scale(aggr, config->scale, &counter->counts->scaled);
315 
316 	for (i = 0; i < 3; i++)
317 		update_stats(&ps->res_stats[i], count[i]);
318 
319 	if (verbose) {
320 		fprintf(config->output, "%s: %" PRIu64 " %" PRIu64 " %" PRIu64 "\n",
321 			perf_evsel__name(counter), count[0], count[1], count[2]);
322 	}
323 
324 	/*
325 	 * Save the full runtime - to allow normalization during printout:
326 	 */
327 	perf_stat__update_shadow_stats(counter, count, 0);
328 
329 	return 0;
330 }
331