summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/stat-shadow.c
blob: 9d22cde09dc964d340fa46dfd52c9e54df97721f (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
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
// SPDX-License-Identifier: GPL-2.0
#include <math.h>
#include <stdio.h>
#include "evsel.h"
#include "stat.h"
#include "color.h"
#include "debug.h"
#include "pmu.h"
#include "rblist.h"
#include "evlist.h"
#include "expr.h"
#include "metricgroup.h"
#include "cgroup.h"
#include "units.h"
#include <linux/zalloc.h>
#include "iostat.h"
#include "util/hashmap.h"

/*
 * AGGR_GLOBAL: Use CPU 0
 * AGGR_SOCKET: Use first CPU of socket
 * AGGR_DIE: Use first CPU of die
 * AGGR_CORE: Use first CPU of core
 * AGGR_NONE: Use matching CPU
 * AGGR_THREAD: Not supported?
 */

struct stats walltime_nsecs_stats;
struct rusage_stats ru_stats;

static struct runtime_stat {
	struct rblist value_list;
} rt_stat;

enum {
	CTX_BIT_USER	= 1 << 0,
	CTX_BIT_KERNEL	= 1 << 1,
	CTX_BIT_HV	= 1 << 2,
	CTX_BIT_HOST	= 1 << 3,
	CTX_BIT_IDLE	= 1 << 4,
	CTX_BIT_MAX	= 1 << 5,
};

enum stat_type {
	STAT_NONE = 0,
	STAT_NSECS,
	STAT_CYCLES,
	STAT_INSTRUCTIONS,
	STAT_STALLED_CYCLES_FRONT,
	STAT_STALLED_CYCLES_BACK,
	STAT_BRANCHES,
	STAT_BRANCH_MISS,
	STAT_CACHE_REFS,
	STAT_CACHE_MISSES,
	STAT_L1_DCACHE,
	STAT_L1_ICACHE,
	STAT_LL_CACHE,
	STAT_ITLB_CACHE,
	STAT_DTLB_CACHE,
	STAT_L1D_MISS,
	STAT_L1I_MISS,
	STAT_LL_MISS,
	STAT_DTLB_MISS,
	STAT_ITLB_MISS,
	STAT_MAX
};

struct saved_value {
	struct rb_node rb_node;
	struct evsel *evsel;
	enum stat_type type;
	int ctx;
	int map_idx;  /* cpu or thread map index */
	struct cgroup *cgrp;
	struct stats stats;
	u64 metric_total;
	int metric_other;
};

static int saved_value_cmp(struct rb_node *rb_node, const void *entry)
{
	struct saved_value *a = container_of(rb_node,
					     struct saved_value,
					     rb_node);
	const struct saved_value *b = entry;

	if (a->map_idx != b->map_idx)
		return a->map_idx - b->map_idx;

	/*
	 * Previously the rbtree was used to link generic metrics.
	 * The keys were evsel/cpu. Now the rbtree is extended to support
	 * per-thread shadow stats. For shadow stats case, the keys
	 * are cpu/type/ctx/stat (evsel is NULL). For generic metrics
	 * case, the keys are still evsel/cpu (type/ctx/stat are 0 or NULL).
	 */
	if (a->type != b->type)
		return a->type - b->type;

	if (a->ctx != b->ctx)
		return a->ctx - b->ctx;

	if (a->cgrp != b->cgrp)
		return (char *)a->cgrp < (char *)b->cgrp ? -1 : +1;

	if (a->evsel == b->evsel)
		return 0;
	if ((char *)a->evsel < (char *)b->evsel)
		return -1;
	return +1;
}

static struct rb_node *saved_value_new(struct rblist *rblist __maybe_unused,
				     const void *entry)
{
	struct saved_value *nd = malloc(sizeof(struct saved_value));

	if (!nd)
		return NULL;
	memcpy(nd, entry, sizeof(struct saved_value));
	return &nd->rb_node;
}

static void saved_value_delete(struct rblist *rblist __maybe_unused,
			       struct rb_node *rb_node)
{
	struct saved_value *v;

	BUG_ON(!rb_node);
	v = container_of(rb_node, struct saved_value, rb_node);
	free(v);
}

static struct saved_value *saved_value_lookup(struct evsel *evsel,
					      int map_idx,
					      bool create,
					      enum stat_type type,
					      int ctx,
					      struct cgroup *cgrp)
{
	struct rblist *rblist;
	struct rb_node *nd;
	struct saved_value dm = {
		.map_idx = map_idx,
		.evsel = evsel,
		.type = type,
		.ctx = ctx,
		.cgrp = cgrp,
	};

	rblist = &rt_stat.value_list;

	/* don't use context info for clock events */
	if (type == STAT_NSECS)
		dm.ctx = 0;

	nd = rblist__find(rblist, &dm);
	if (nd)
		return container_of(nd, struct saved_value, rb_node);
	if (create) {
		rblist__add_node(rblist, &dm);
		nd = rblist__find(rblist, &dm);
		if (nd)
			return container_of(nd, struct saved_value, rb_node);
	}
	return NULL;
}

void perf_stat__init_shadow_stats(void)
{
	struct rblist *rblist = &rt_stat.value_list;

	rblist__init(rblist);
	rblist->node_cmp = saved_value_cmp;
	rblist->node_new = saved_value_new;
	rblist->node_delete = saved_value_delete;
}

static int evsel_context(const struct evsel *evsel)
{
	int ctx = 0;

	if (evsel->core.attr.exclude_kernel)
		ctx |= CTX_BIT_KERNEL;
	if (evsel->core.attr.exclude_user)
		ctx |= CTX_BIT_USER;
	if (evsel->core.attr.exclude_hv)
		ctx |= CTX_BIT_HV;
	if (evsel->core.attr.exclude_host)
		ctx |= CTX_BIT_HOST;
	if (evsel->core.attr.exclude_idle)
		ctx |= CTX_BIT_IDLE;

	return ctx;
}

void perf_stat__reset_shadow_per_stat(void)
{
	struct rblist *rblist;
	struct rb_node *pos, *next;

	rblist = &rt_stat.value_list;
	next = rb_first_cached(&rblist->entries);
	while (next) {
		pos = next;
		next = rb_next(pos);
		memset(&container_of(pos, struct saved_value, rb_node)->stats,
		       0,
		       sizeof(struct stats));
	}
}

void perf_stat__reset_shadow_stats(void)
{
	perf_stat__reset_shadow_per_stat();
	memset(&walltime_nsecs_stats, 0, sizeof(walltime_nsecs_stats));
	memset(&ru_stats, 0, sizeof(ru_stats));
}

struct runtime_stat_data {
	int ctx;
	struct cgroup *cgrp;
};

static void update_runtime_stat(enum stat_type type,
				int map_idx, u64 count,
				struct runtime_stat_data *rsd)
{
	struct saved_value *v = saved_value_lookup(NULL, map_idx, true, type,
						   rsd->ctx, rsd->cgrp);

	if (v)
		update_stats(&v->stats, count);
}

/*
 * Update various tracking values we maintain to print
 * more semantic information such as miss/hit ratios,
 * instruction rates, etc:
 */
void perf_stat__update_shadow_stats(struct evsel *counter, u64 count,
				    int aggr_idx)
{
	u64 count_ns = count;
	struct runtime_stat_data rsd = {
		.ctx = evsel_context(counter),
		.cgrp = counter->cgrp,
	};
	count *= counter->scale;

	if (evsel__is_clock(counter))
		update_runtime_stat(STAT_NSECS, aggr_idx, count_ns, &rsd);
	else if (evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
		update_runtime_stat(STAT_CYCLES, aggr_idx, count, &rsd);
	else if (evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_FRONTEND))
		update_runtime_stat(STAT_STALLED_CYCLES_FRONT,
				    aggr_idx, count, &rsd);
	else if (evsel__match(counter, HARDWARE, HW_STALLED_CYCLES_BACKEND))
		update_runtime_stat(STAT_STALLED_CYCLES_BACK,
				    aggr_idx, count, &rsd);
	else if (evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
		update_runtime_stat(STAT_BRANCHES, aggr_idx, count, &rsd);
	else if (evsel__match(counter, HARDWARE, HW_CACHE_REFERENCES))
		update_runtime_stat(STAT_CACHE_REFS, aggr_idx, count, &rsd);
	else if (evsel__match(counter, HW_CACHE, HW_CACHE_L1D))
		update_runtime_stat(STAT_L1_DCACHE, aggr_idx, count, &rsd);
	else if (evsel__match(counter, HW_CACHE, HW_CACHE_L1I))
		update_runtime_stat(STAT_L1_ICACHE, aggr_idx, count, &rsd);
	else if (evsel__match(counter, HW_CACHE, HW_CACHE_LL))
		update_runtime_stat(STAT_LL_CACHE, aggr_idx, count, &rsd);
	else if (evsel__match(counter, HW_CACHE, HW_CACHE_DTLB))
		update_runtime_stat(STAT_DTLB_CACHE, aggr_idx, count, &rsd);
	else if (evsel__match(counter, HW_CACHE, HW_CACHE_ITLB))
		update_runtime_stat(STAT_ITLB_CACHE, aggr_idx, count, &rsd);
}

static enum stat_type evsel__stat_type(const struct evsel *evsel)
{
	/* Fake perf_hw_cache_op_id values for use with evsel__match. */
	u64 PERF_COUNT_hw_cache_l1d_miss = PERF_COUNT_HW_CACHE_L1D |
		((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
		((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16);
	u64 PERF_COUNT_hw_cache_l1i_miss = PERF_COUNT_HW_CACHE_L1I |
		((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
		((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16);
	u64 PERF_COUNT_hw_cache_ll_miss = PERF_COUNT_HW_CACHE_LL |
		((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
		((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16);
	u64 PERF_COUNT_hw_cache_dtlb_miss = PERF_COUNT_HW_CACHE_DTLB |
		((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
		((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16);
	u64 PERF_COUNT_hw_cache_itlb_miss = PERF_COUNT_HW_CACHE_ITLB |
		((PERF_COUNT_HW_CACHE_OP_READ) << 8) |
		((PERF_COUNT_HW_CACHE_RESULT_MISS) << 16);

	if (evsel__is_clock(evsel))
		return STAT_NSECS;
	else if (evsel__match(evsel, HARDWARE, HW_CPU_CYCLES))
		return STAT_CYCLES;
	else if (evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS))
		return STAT_INSTRUCTIONS;
	else if (evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES_FRONTEND))
		return STAT_STALLED_CYCLES_FRONT;
	else if (evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES_BACKEND))
		return STAT_STALLED_CYCLES_BACK;
	else if (evsel__match(evsel, HARDWARE, HW_BRANCH_INSTRUCTIONS))
		return STAT_BRANCHES;
	else if (evsel__match(evsel, HARDWARE, HW_BRANCH_MISSES))
		return STAT_BRANCH_MISS;
	else if (evsel__match(evsel, HARDWARE, HW_CACHE_REFERENCES))
		return STAT_CACHE_REFS;
	else if (evsel__match(evsel, HARDWARE, HW_CACHE_MISSES))
		return STAT_CACHE_MISSES;
	else if (evsel__match(evsel, HW_CACHE, HW_CACHE_L1D))
		return STAT_L1_DCACHE;
	else if (evsel__match(evsel, HW_CACHE, HW_CACHE_L1I))
		return STAT_L1_ICACHE;
	else if (evsel__match(evsel, HW_CACHE, HW_CACHE_LL))
		return STAT_LL_CACHE;
	else if (evsel__match(evsel, HW_CACHE, HW_CACHE_DTLB))
		return STAT_DTLB_CACHE;
	else if (evsel__match(evsel, HW_CACHE, HW_CACHE_ITLB))
		return STAT_ITLB_CACHE;
	else if (evsel__match(evsel, HW_CACHE, hw_cache_l1d_miss))
		return STAT_L1D_MISS;
	else if (evsel__match(evsel, HW_CACHE, hw_cache_l1i_miss))
		return STAT_L1I_MISS;
	else if (evsel__match(evsel, HW_CACHE, hw_cache_ll_miss))
		return STAT_LL_MISS;
	else if (evsel__match(evsel, HW_CACHE, hw_cache_dtlb_miss))
		return STAT_DTLB_MISS;
	else if (evsel__match(evsel, HW_CACHE, hw_cache_itlb_miss))
		return STAT_ITLB_MISS;
	return STAT_NONE;
}

static const char *get_ratio_color(const double ratios[3], double val)
{
	const char *color = PERF_COLOR_NORMAL;

	if (val > ratios[0])
		color = PERF_COLOR_RED;
	else if (val > ratios[1])
		color = PERF_COLOR_MAGENTA;
	else if (val > ratios[2])
		color = PERF_COLOR_YELLOW;

	return color;
}

static double find_stat(const struct evsel *evsel, int aggr_idx, enum stat_type type)
{
	const struct evsel *cur;
	int evsel_ctx = evsel_context(evsel);

	evlist__for_each_entry(evsel->evlist, cur) {
		struct perf_stat_aggr *aggr;

		/* Ignore the evsel that is being searched from. */
		if (evsel == cur)
			continue;

		/* Ignore evsels that are part of different groups. */
		if (evsel->core.leader->nr_members &&
		    evsel->core.leader != cur->core.leader)
			continue;
		/* Ignore evsels with mismatched modifiers. */
		if (evsel_ctx != evsel_context(cur))
			continue;
		/* Ignore if not the cgroup we're looking for. */
		if (evsel->cgrp != cur->cgrp)
			continue;
		/* Ignore if not the stat we're looking for. */
		if (type != evsel__stat_type(cur))
			continue;

		aggr = &cur->stats->aggr[aggr_idx];
		if (type == STAT_NSECS)
			return aggr->counts.val;
		return aggr->counts.val * cur->scale;
	}
	return 0.0;
}

static void print_ratio(struct perf_stat_config *config,
			const struct evsel *evsel, int aggr_idx,
			double numerator, struct perf_stat_output_ctx *out,
			enum stat_type denominator_type,
			const double color_ratios[3], const char *unit)
{
	double denominator = find_stat(evsel, aggr_idx, denominator_type);

	if (numerator && denominator) {
		double ratio = numerator / denominator * 100.0;
		const char *color = get_ratio_color(color_ratios, ratio);

		out->print_metric(config, out->ctx, color, "%7.2f%%", unit, ratio);
	} else
		out->print_metric(config, out->ctx, NULL, NULL, unit, 0);
}

static void print_stalled_cycles_front(struct perf_stat_config *config,
				const struct evsel *evsel,
				int aggr_idx, double stalled,
				struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {50.0, 30.0, 10.0};

	print_ratio(config, evsel, aggr_idx, stalled, out, STAT_CYCLES, color_ratios,
		    "frontend cycles idle");
}

static void print_stalled_cycles_back(struct perf_stat_config *config,
				const struct evsel *evsel,
				int aggr_idx, double stalled,
				struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {75.0, 50.0, 20.0};

	print_ratio(config, evsel, aggr_idx, stalled, out, STAT_CYCLES, color_ratios,
		    "backend cycles idle");
}

static void print_branch_miss(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double misses,
			struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {20.0, 10.0, 5.0};

	print_ratio(config, evsel, aggr_idx, misses, out, STAT_BRANCHES, color_ratios,
		    "of all branches");
}

static void print_l1d_miss(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double misses,
			struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {20.0, 10.0, 5.0};

	print_ratio(config, evsel, aggr_idx, misses, out, STAT_L1_DCACHE, color_ratios,
		    "of all L1-dcache accesses");
}

static void print_l1i_miss(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double misses,
			struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {20.0, 10.0, 5.0};

	print_ratio(config, evsel, aggr_idx, misses, out, STAT_L1_ICACHE, color_ratios,
		    "of all L1-icache accesses");
}

static void print_ll_miss(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double misses,
			struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {20.0, 10.0, 5.0};

	print_ratio(config, evsel, aggr_idx, misses, out, STAT_LL_CACHE, color_ratios,
		    "of all L1-icache accesses");
}

static void print_dtlb_miss(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double misses,
			struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {20.0, 10.0, 5.0};

	print_ratio(config, evsel, aggr_idx, misses, out, STAT_DTLB_CACHE, color_ratios,
		    "of all dTLB cache accesses");
}

static void print_itlb_miss(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double misses,
			struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {20.0, 10.0, 5.0};

	print_ratio(config, evsel, aggr_idx, misses, out, STAT_ITLB_CACHE, color_ratios,
		    "of all iTLB cache accesses");
}

static void print_cache_miss(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double misses,
			struct perf_stat_output_ctx *out)
{
	static const double color_ratios[3] = {20.0, 10.0, 5.0};

	print_ratio(config, evsel, aggr_idx, misses, out, STAT_CACHE_REFS, color_ratios,
		    "of all cache refs");
}

static void print_instructions(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double instructions,
			struct perf_stat_output_ctx *out)
{
	print_metric_t print_metric = out->print_metric;
	void *ctxp = out->ctx;
	double cycles = find_stat(evsel, aggr_idx, STAT_CYCLES);
	double max_stalled = max(find_stat(evsel, aggr_idx, STAT_STALLED_CYCLES_FRONT),
				find_stat(evsel, aggr_idx, STAT_STALLED_CYCLES_BACK));

	if (cycles) {
		print_metric(config, ctxp, NULL, "%7.2f ", "insn per cycle",
			instructions / cycles);
	} else
		print_metric(config, ctxp, NULL, NULL, "insn per cycle", 0);

	if (max_stalled && instructions) {
		out->new_line(config, ctxp);
		print_metric(config, ctxp, NULL, "%7.2f ", "stalled cycles per insn",
			max_stalled / instructions);
	}
}

static void print_cycles(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx, double cycles,
			struct perf_stat_output_ctx *out)
{
	double nsecs = find_stat(evsel, aggr_idx, STAT_NSECS);

	if (cycles && nsecs) {
		double ratio = cycles / nsecs;

		out->print_metric(config, out->ctx, NULL, "%8.3f", "GHz", ratio);
	} else
		out->print_metric(config, out->ctx, NULL, NULL, "GHz", 0);
}

static void print_nsecs(struct perf_stat_config *config,
			const struct evsel *evsel,
			int aggr_idx __maybe_unused, double nsecs,
			struct perf_stat_output_ctx *out)
{
	print_metric_t print_metric = out->print_metric;
	void *ctxp = out->ctx;
	double wall_time = avg_stats(&walltime_nsecs_stats);

	if (wall_time) {
		print_metric(config, ctxp, NULL, "%8.3f", "CPUs utilized",
			nsecs / (wall_time * evsel->scale));
	} else
		print_metric(config, ctxp, NULL, NULL, "CPUs utilized", 0);
}

static int prepare_metric(struct evsel **metric_events,
			  struct metric_ref *metric_refs,
			  struct expr_parse_ctx *pctx,
			  int aggr_idx)
{
	int i;

	for (i = 0; metric_events[i]; i++) {
		char *n;
		double val;
		int source_count = 0;

		if (evsel__is_tool(metric_events[i])) {
			struct stats *stats;
			double scale;

			switch (metric_events[i]->tool_event) {
			case PERF_TOOL_DURATION_TIME:
				stats = &walltime_nsecs_stats;
				scale = 1e-9;
				break;
			case PERF_TOOL_USER_TIME:
				stats = &ru_stats.ru_utime_usec_stat;
				scale = 1e-6;
				break;
			case PERF_TOOL_SYSTEM_TIME:
				stats = &ru_stats.ru_stime_usec_stat;
				scale = 1e-6;
				break;
			case PERF_TOOL_NONE:
				pr_err("Invalid tool event 'none'");
				abort();
			case PERF_TOOL_MAX:
				pr_err("Invalid tool event 'max'");
				abort();
			default:
				pr_err("Unknown tool event '%s'", evsel__name(metric_events[i]));
				abort();
			}
			val = avg_stats(stats) * scale;
			source_count = 1;
		} else {
			struct perf_stat_evsel *ps = metric_events[i]->stats;
			struct perf_stat_aggr *aggr = &ps->aggr[aggr_idx];

			if (!aggr)
				break;

			/*
			 * If an event was scaled during stat gathering, reverse
			 * the scale before computing the metric.
			 */
			val = aggr->counts.val * (1.0 / metric_events[i]->scale);
			source_count = evsel__source_count(metric_events[i]);
		}
		n = strdup(evsel__metric_id(metric_events[i]));
		if (!n)
			return -ENOMEM;

		expr__add_id_val_source_count(pctx, n, val, source_count);
	}

	for (int j = 0; metric_refs && metric_refs[j].metric_name; j++) {
		int ret = expr__add_ref(pctx, &metric_refs[j]);

		if (ret)
			return ret;
	}

	return i;
}

static void generic_metric(struct perf_stat_config *config,
			   const char *metric_expr,
			   const char *metric_threshold,
			   struct evsel **metric_events,
			   struct metric_ref *metric_refs,
			   char *name,
			   const char *metric_name,
			   const char *metric_unit,
			   int runtime,
			   int aggr_idx,
			   struct perf_stat_output_ctx *out)
{
	print_metric_t print_metric = out->print_metric;
	struct expr_parse_ctx *pctx;
	double ratio, scale, threshold;
	int i;
	void *ctxp = out->ctx;
	const char *color = NULL;

	pctx = expr__ctx_new();
	if (!pctx)
		return;

	if (config->user_requested_cpu_list)
		pctx->sctx.user_requested_cpu_list = strdup(config->user_requested_cpu_list);
	pctx->sctx.runtime = runtime;
	pctx->sctx.system_wide = config->system_wide;
	i = prepare_metric(metric_events, metric_refs, pctx, aggr_idx);
	if (i < 0) {
		expr__ctx_free(pctx);
		return;
	}
	if (!metric_events[i]) {
		if (expr__parse(&ratio, pctx, metric_expr) == 0) {
			char *unit;
			char metric_bf[64];

			if (metric_threshold &&
			    expr__parse(&threshold, pctx, metric_threshold) == 0 &&
			    !isnan(threshold)) {
				color = fpclassify(threshold) == FP_ZERO
					? PERF_COLOR_GREEN : PERF_COLOR_RED;
			}

			if (metric_unit && metric_name) {
				if (perf_pmu__convert_scale(metric_unit,
					&unit, &scale) >= 0) {
					ratio *= scale;
				}
				if (strstr(metric_expr, "?"))
					scnprintf(metric_bf, sizeof(metric_bf),
					  "%s  %s_%d", unit, metric_name, runtime);
				else
					scnprintf(metric_bf, sizeof(metric_bf),
					  "%s  %s", unit, metric_name);

				print_metric(config, ctxp, color, "%8.1f",
					     metric_bf, ratio);
			} else {
				print_metric(config, ctxp, color, "%8.2f",
					metric_name ?
					metric_name :
					out->force_header ?  name : "",
					ratio);
			}
		} else {
			print_metric(config, ctxp, color, /*unit=*/NULL,
				     out->force_header ?
				     (metric_name ? metric_name : name) : "", 0);
		}
	} else {
		print_metric(config, ctxp, color, /*unit=*/NULL,
			     out->force_header ?
			     (metric_name ? metric_name : name) : "", 0);
	}

	expr__ctx_free(pctx);
}

double test_generic_metric(struct metric_expr *mexp, int aggr_idx)
{
	struct expr_parse_ctx *pctx;
	double ratio = 0.0;

	pctx = expr__ctx_new();
	if (!pctx)
		return NAN;

	if (prepare_metric(mexp->metric_events, mexp->metric_refs, pctx, aggr_idx) < 0)
		goto out;

	if (expr__parse(&ratio, pctx, mexp->metric_expr))
		ratio = 0.0;

out:
	expr__ctx_free(pctx);
	return ratio;
}

void perf_stat__print_shadow_stats(struct perf_stat_config *config,
				   struct evsel *evsel,
				   double avg, int aggr_idx,
				   struct perf_stat_output_ctx *out,
				   struct rblist *metric_events)
{
	typedef void (*stat_print_function_t)(struct perf_stat_config *config,
					const struct evsel *evsel,
					int aggr_idx, double misses,
					struct perf_stat_output_ctx *out);
	static const stat_print_function_t stat_print_function[STAT_MAX] = {
		[STAT_INSTRUCTIONS] = print_instructions,
		[STAT_BRANCH_MISS] = print_branch_miss,
		[STAT_L1D_MISS] = print_l1d_miss,
		[STAT_L1I_MISS] = print_l1i_miss,
		[STAT_DTLB_MISS] = print_dtlb_miss,
		[STAT_ITLB_MISS] = print_itlb_miss,
		[STAT_LL_MISS] = print_ll_miss,
		[STAT_CACHE_MISSES] = print_cache_miss,
		[STAT_STALLED_CYCLES_FRONT] = print_stalled_cycles_front,
		[STAT_STALLED_CYCLES_BACK] = print_stalled_cycles_back,
		[STAT_CYCLES] = print_cycles,
		[STAT_NSECS] = print_nsecs,
	};
	print_metric_t print_metric = out->print_metric;
	void *ctxp = out->ctx;
	struct metric_event *me;
	int num = 1;

	if (config->iostat_run) {
		iostat_print_metric(config, evsel, out);
	} else {
		stat_print_function_t fn = stat_print_function[evsel__stat_type(evsel)];

		if (fn)
			fn(config, evsel, aggr_idx, avg, out);
		else {
			double nsecs =	find_stat(evsel, aggr_idx, STAT_NSECS);

			if (nsecs) {
				char unit = ' ';
				char unit_buf[10] = "/sec";
				double ratio = convert_unit_double(1000000000.0 * avg / nsecs,
								   &unit);

				if (unit != ' ')
					snprintf(unit_buf, sizeof(unit_buf), "%c/sec", unit);
				print_metric(config, ctxp, NULL, "%8.3f", unit_buf, ratio);
			} else
				num = 0;
		}
	}

	if ((me = metricgroup__lookup(metric_events, evsel, false)) != NULL) {
		struct metric_expr *mexp;

		list_for_each_entry (mexp, &me->head, nd) {
			if (num++ > 0)
				out->new_line(config, ctxp);
			generic_metric(config, mexp->metric_expr, mexp->metric_threshold,
				       mexp->metric_events, mexp->metric_refs, evsel->name,
				       mexp->metric_name, mexp->metric_unit, mexp->runtime,
				       aggr_idx, out);
		}
	}
	if (num == 0)
		print_metric(config, ctxp, NULL, NULL, NULL, 0);
}