perf test: Add a test case for hists__{match,link}

As they are used from diff and event group report, add a test case to
verify their behaviors.

In this test I made a fake machine and two evsel. Each evsel got 10
samples (so hist entries) - 5 are common and the rests are not. So
after hists__match() both of them will have 5 entries with pair set.

And the second evsel has a collapsed entry so that the total number is 9
- I made it in order to simulate more realistic case. Thus after
hists__link the first entry will have 14 entries - 5 are common (w/
pair), 5 are unmatch (w/o pair) and 4 are dummy (w/ pair). And the
second entry will have 9 entries all have its pair.

Signed-off-by: Namhyung Kim <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
[ committer note: fixed up clashes with cset that moved methods to machine.h ]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Makefile

···
 LIB_OBJS += $(OUTPUT)tests/evsel-roundtrip-name.o
 LIB_OBJS += $(OUTPUT)tests/evsel-tp-sched.o
 LIB_OBJS += $(OUTPUT)tests/pmu.o
+LIB_OBJS += $(OUTPUT)tests/hists_link.o
 
 BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
 BUILTIN_OBJS += $(OUTPUT)builtin-bench.o

tools/perf/tests/builtin-test.c

···
 		.func = test__attr,
 	},
 	{
+		.desc = "Test matching and linking mutliple hists",
+		.func = test__hists_link,
+	},
+	{
 		.func = NULL,
 	},
 };

tools/perf/tests/hists_link.c

···
+#include "perf.h"
+#include "tests.h"
+#include "debug.h"
+#include "symbol.h"
+#include "sort.h"
+#include "evsel.h"
+#include "evlist.h"
+#include "machine.h"
+#include "thread.h"
+#include "parse-events.h"
+
+static struct {
+	u32 pid;
+	const char *comm;
+} fake_threads[] = {
+	{ 100, "perf" },
+	{ 200, "perf" },
+	{ 300, "bash" },
+};
+
+static struct {
+	u32 pid;
+	u64 start;
+	const char *filename;
+} fake_mmap_info[] = {
+	{ 100, 0x40000, "perf" },
+	{ 100, 0x50000, "libc" },
+	{ 100, 0xf0000, "[kernel]" },
+	{ 200, 0x40000, "perf" },
+	{ 200, 0x50000, "libc" },
+	{ 200, 0xf0000, "[kernel]" },
+	{ 300, 0x40000, "bash" },
+	{ 300, 0x50000, "libc" },
+	{ 300, 0xf0000, "[kernel]" },
+};
+
+struct fake_sym {
+	u64 start;
+	u64 length;
+	const char *name;
+};
+
+static struct fake_sym perf_syms[] = {
+	{ 700, 100, "main" },
+	{ 800, 100, "run_command" },
+	{ 900, 100, "cmd_record" },
+};
+
+static struct fake_sym bash_syms[] = {
+	{ 700, 100, "main" },
+	{ 800, 100, "xmalloc" },
+	{ 900, 100, "xfree" },
+};
+
+static struct fake_sym libc_syms[] = {
+	{ 700, 100, "malloc" },
+	{ 800, 100, "free" },
+	{ 900, 100, "realloc" },
+};
+
+static struct fake_sym kernel_syms[] = {
+	{ 700, 100, "schedule" },
+	{ 800, 100, "page_fault" },
+	{ 900, 100, "sys_perf_event_open" },
+};
+
+static struct {
+	const char *dso_name;
+	struct fake_sym *syms;
+	size_t nr_syms;
+} fake_symbols[] = {
+	{ "perf", perf_syms, ARRAY_SIZE(perf_syms) },
+	{ "bash", bash_syms, ARRAY_SIZE(bash_syms) },
+	{ "libc", libc_syms, ARRAY_SIZE(libc_syms) },
+	{ "[kernel]", kernel_syms, ARRAY_SIZE(kernel_syms) },
+};
+
+static struct machine *setup_fake_machine(void)
+{
+	struct rb_root machine_root = RB_ROOT;
+	struct machine *machine;
+	size_t i;
+
+	machine = machines__findnew(&machine_root, HOST_KERNEL_ID);
+	if (machine == NULL) {
+		pr_debug("Not enough memory for machine setup\n");
+		return NULL;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(fake_threads); i++) {
+		struct thread *thread;
+
+		thread = machine__findnew_thread(machine, fake_threads[i].pid);
+		if (thread == NULL)
+			goto out;
+
+		thread__set_comm(thread, fake_threads[i].comm);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(fake_mmap_info); i++) {
+		union perf_event fake_mmap_event = {
+			.mmap = {
+				.header = { .misc = PERF_RECORD_MISC_USER, },
+				.pid = fake_mmap_info[i].pid,
+				.start = fake_mmap_info[i].start,
+				.len = 0x1000ULL,
+				.pgoff = 0ULL,
+			},
+		};
+
+		strcpy(fake_mmap_event.mmap.filename,
+		       fake_mmap_info[i].filename);
+
+		machine__process_mmap_event(machine, &fake_mmap_event);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(fake_symbols); i++) {
+		size_t k;
+		struct dso *dso;
+
+		dso = __dsos__findnew(&machine->user_dsos,
+				      fake_symbols[i].dso_name);
+		if (dso == NULL)
+			goto out;
+
+		/* emulate dso__load() */
+		dso__set_loaded(dso, MAP__FUNCTION);
+
+		for (k = 0; k < fake_symbols[i].nr_syms; k++) {
+			struct symbol *sym;
+			struct fake_sym *fsym = &fake_symbols[i].syms[k];
+
+			sym = symbol__new(fsym->start, fsym->length,
+					  STB_GLOBAL, fsym->name);
+			if (sym == NULL)
+				goto out;
+
+			symbols__insert(&dso->symbols[MAP__FUNCTION], sym);
+		}
+	}
+
+	return machine;
+
+out:
+	pr_debug("Not enough memory for machine setup\n");
+	machine__delete_threads(machine);
+	machine__delete(machine);
+	return NULL;
+}
+
+struct sample {
+	u32 pid;
+	u64 ip;
+	struct thread *thread;
+	struct map *map;
+	struct symbol *sym;
+};
+
+static struct sample fake_common_samples[] = {
+	/* perf [kernel] schedule() */
+	{ .pid = 100, .ip = 0xf0000 + 700, },
+	/* perf [perf]   main() */
+	{ .pid = 200, .ip = 0x40000 + 700, },
+	/* perf [perf]   cmd_record() */
+	{ .pid = 200, .ip = 0x40000 + 900, },
+	/* bash [bash]   xmalloc() */
+	{ .pid = 300, .ip = 0x40000 + 800, },
+	/* bash [libc]   malloc() */
+	{ .pid = 300, .ip = 0x50000 + 700, },
+};
+
+static struct sample fake_samples[][5] = {
+	{
+		/* perf [perf]   run_command() */
+		{ .pid = 100, .ip = 0x40000 + 800, },
+		/* perf [libc]   malloc() */
+		{ .pid = 100, .ip = 0x50000 + 700, },
+		/* perf [kernel] page_fault() */
+		{ .pid = 100, .ip = 0xf0000 + 800, },
+		/* perf [kernel] sys_perf_event_open() */
+		{ .pid = 200, .ip = 0xf0000 + 900, },
+		/* bash [libc]   free() */
+		{ .pid = 300, .ip = 0x50000 + 800, },
+	},
+	{
+		/* perf [libc]   free() */
+		{ .pid = 200, .ip = 0x50000 + 800, },
+		/* bash [libc]   malloc() */
+		{ .pid = 300, .ip = 0x50000 + 700, }, /* will be merged */
+		/* bash [bash]   xfee() */
+		{ .pid = 300, .ip = 0x40000 + 900, },
+		/* bash [libc]   realloc() */
+		{ .pid = 300, .ip = 0x50000 + 900, },
+		/* bash [kernel] page_fault() */
+		{ .pid = 300, .ip = 0xf0000 + 800, },
+	},
+};
+
+static int add_hist_entries(struct perf_evlist *evlist, struct machine *machine)
+{
+	struct perf_evsel *evsel;
+	struct addr_location al;
+	struct hist_entry *he;
+	struct perf_sample sample = { .cpu = 0, };
+	size_t i = 0, k;
+
+	/*
+	 * each evsel will have 10 samples - 5 common and 5 distinct.
+	 * However the second evsel also has a collapsed entry for
+	 * "bash [libc] malloc" so total 9 entries will be in the tree.
+	 */
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		for (k = 0; k < ARRAY_SIZE(fake_common_samples); k++) {
+			const union perf_event event = {
+				.ip = {
+					.header = {
+						.misc = PERF_RECORD_MISC_USER,
+					},
+					.pid = fake_common_samples[k].pid,
+					.ip  = fake_common_samples[k].ip,
+				},
+			};
+
+			if (perf_event__preprocess_sample(&event, machine, &al,
+							  &sample, 0) < 0)
+				goto out;
+
+			he = __hists__add_entry(&evsel->hists, &al, NULL, 1);
+			if (he == NULL)
+				goto out;
+
+			fake_common_samples[k].thread = al.thread;
+			fake_common_samples[k].map = al.map;
+			fake_common_samples[k].sym = al.sym;
+		}
+
+		for (k = 0; k < ARRAY_SIZE(fake_samples[i]); k++) {
+			const union perf_event event = {
+				.ip = {
+					.header = {
+						.misc = PERF_RECORD_MISC_USER,
+					},
+					.pid = fake_samples[i][k].pid,
+					.ip  = fake_samples[i][k].ip,
+				},
+			};
+
+			if (perf_event__preprocess_sample(&event, machine, &al,
+							  &sample, 0) < 0)
+				goto out;
+
+			he = __hists__add_entry(&evsel->hists, &al, NULL, 1);
+			if (he == NULL)
+				goto out;
+
+			fake_samples[i][k].thread = al.thread;
+			fake_samples[i][k].map = al.map;
+			fake_samples[i][k].sym = al.sym;
+		}
+		i++;
+	}
+
+	return 0;
+
+out:
+	pr_debug("Not enough memory for adding a hist entry\n");
+	return -1;
+}
+
+static int find_sample(struct sample *samples, size_t nr_samples,
+		       struct thread *t, struct map *m, struct symbol *s)
+{
+	while (nr_samples--) {
+		if (samples->thread == t && samples->map == m &&
+		    samples->sym == s)
+			return 1;
+		samples++;
+	}
+	return 0;
+}
+
+static int __validate_match(struct hists *hists)
+{
+	size_t count = 0;
+	struct rb_root *root;
+	struct rb_node *node;
+
+	/*
+	 * Only entries from fake_common_samples should have a pair.
+	 */
+	if (sort__need_collapse)
+		root = &hists->entries_collapsed;
+	else
+		root = hists->entries_in;
+
+	node = rb_first(root);
+	while (node) {
+		struct hist_entry *he;
+
+		he = rb_entry(node, struct hist_entry, rb_node_in);
+
+		if (hist_entry__has_pairs(he)) {
+			if (find_sample(fake_common_samples,
+					ARRAY_SIZE(fake_common_samples),
+					he->thread, he->ms.map, he->ms.sym)) {
+				count++;
+			} else {
+				pr_debug("Can't find the matched entry\n");
+				return -1;
+			}
+		}
+
+		node = rb_next(node);
+	}
+
+	if (count != ARRAY_SIZE(fake_common_samples)) {
+		pr_debug("Invalid count for matched entries: %zd of %zd\n",
+			 count, ARRAY_SIZE(fake_common_samples));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int validate_match(struct hists *leader, struct hists *other)
+{
+	return __validate_match(leader) || __validate_match(other);
+}
+
+static int __validate_link(struct hists *hists, int idx)
+{
+	size_t count = 0;
+	size_t count_pair = 0;
+	size_t count_dummy = 0;
+	struct rb_root *root;
+	struct rb_node *node;
+
+	/*
+	 * Leader hists (idx = 0) will have dummy entries from other,
+	 * and some entries will have no pair.  However every entry
+	 * in other hists should have (dummy) pair.
+	 */
+	if (sort__need_collapse)
+		root = &hists->entries_collapsed;
+	else
+		root = hists->entries_in;
+
+	node = rb_first(root);
+	while (node) {
+		struct hist_entry *he;
+
+		he = rb_entry(node, struct hist_entry, rb_node_in);
+
+		if (hist_entry__has_pairs(he)) {
+			if (!find_sample(fake_common_samples,
+					 ARRAY_SIZE(fake_common_samples),
+					 he->thread, he->ms.map, he->ms.sym) &&
+			    !find_sample(fake_samples[idx],
+					 ARRAY_SIZE(fake_samples[idx]),
+					 he->thread, he->ms.map, he->ms.sym)) {
+				count_dummy++;
+			}
+			count_pair++;
+		} else if (idx) {
+			pr_debug("A entry from the other hists should have pair\n");
+			return -1;
+		}
+
+		count++;
+		node = rb_next(node);
+	}
+
+	/*
+	 * Note that we have a entry collapsed in the other (idx = 1) hists.
+	 */
+	if (idx == 0) {
+		if (count_dummy != ARRAY_SIZE(fake_samples[1]) - 1) {
+			pr_debug("Invalid count of dummy entries: %zd of %zd\n",
+				 count_dummy, ARRAY_SIZE(fake_samples[1]) - 1);
+			return -1;
+		}
+		if (count != count_pair + ARRAY_SIZE(fake_samples[0])) {
+			pr_debug("Invalid count of total leader entries: %zd of %zd\n",
+				 count, count_pair + ARRAY_SIZE(fake_samples[0]));
+			return -1;
+		}
+	} else {
+		if (count != count_pair) {
+			pr_debug("Invalid count of total other entries: %zd of %zd\n",
+				 count, count_pair);
+			return -1;
+		}
+		if (count_dummy > 0) {
+			pr_debug("Other hists should not have dummy entries: %zd\n",
+				 count_dummy);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int validate_link(struct hists *leader, struct hists *other)
+{
+	return __validate_link(leader, 0) || __validate_link(other, 1);
+}
+
+static void print_hists(struct hists *hists)
+{
+	int i = 0;
+	struct rb_root *root;
+	struct rb_node *node;
+
+	if (sort__need_collapse)
+		root = &hists->entries_collapsed;
+	else
+		root = hists->entries_in;
+
+	pr_info("----- %s --------\n", __func__);
+	node = rb_first(root);
+	while (node) {
+		struct hist_entry *he;
+
+		he = rb_entry(node, struct hist_entry, rb_node_in);
+
+		pr_info("%2d: entry: %-8s [%-8s] %20s: period = %"PRIu64"\n",
+			i, he->thread->comm, he->ms.map->dso->short_name,
+			he->ms.sym->name, he->stat.period);
+
+		i++;
+		node = rb_next(node);
+	}
+}
+
+int test__hists_link(void)
+{
+	int err = -1;
+	struct machine *machine = NULL;
+	struct perf_evsel *evsel, *first;
+        struct perf_evlist *evlist = perf_evlist__new(NULL, NULL);
+
+	if (evlist == NULL)
+                return -ENOMEM;
+
+	err = parse_events(evlist, "cpu-clock", 0);
+	if (err)
+		goto out;
+	err = parse_events(evlist, "task-clock", 0);
+	if (err)
+		goto out;
+
+	/* default sort order (comm,dso,sym) will be used */
+	setup_sorting(NULL, NULL);
+
+	/* setup threads/dso/map/symbols also */
+	machine = setup_fake_machine();
+	if (!machine)
+		goto out;
+
+	if (verbose > 1)
+		machine__fprintf(machine, stderr);
+
+	/* process sample events */
+	err = add_hist_entries(evlist, machine);
+	if (err < 0)
+		goto out;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		hists__collapse_resort(&evsel->hists);
+
+		if (verbose > 2)
+			print_hists(&evsel->hists);
+	}
+
+	first = perf_evlist__first(evlist);
+	evsel = perf_evlist__last(evlist);
+
+	/* match common entries */
+	hists__match(&first->hists, &evsel->hists);
+	err = validate_match(&first->hists, &evsel->hists);
+	if (err)
+		goto out;
+
+	/* link common and/or dummy entries */
+	hists__link(&first->hists, &evsel->hists);
+	err = validate_link(&first->hists, &evsel->hists);
+	if (err)
+		goto out;
+
+	err = 0;
+
+out:
+	/* tear down everything */
+	perf_evlist__delete(evlist);
+
+	if (machine) {
+		machine__delete_threads(machine);
+		machine__delete(machine);
+	}
+
+	return err;
+}

tools/perf/tests/tests.h

···
 int test__attr(void);
 int test__dso_data(void);
 int test__parse_events(void);
+int test__hists_link(void);
 
 #endif /* TESTS_H */