1/*
2 * builtin-diff.c
3 *
4 * Builtin diff command: Analyze two perf.data input files, look up and read
5 * DSOs and symbol information, sort them and produce a diff.
6 */
7#include "builtin.h"
8
9#include "util/debug.h"
10#include "util/event.h"
11#include "util/hist.h"
12#include "util/session.h"
13#include "util/sort.h"
14#include "util/symbol.h"
15#include "util/util.h"
16
17#include <stdlib.h>
18
19static char const *input_old = "perf.data.old",
20		  *input_new = "perf.data";
21static char	  diff__default_sort_order[] = "dso,symbol";
22static bool  force;
23static bool show_displacement;
24
25static int hists__add_entry(struct hists *self,
26			    struct addr_location *al, u64 period)
27{
28	if (__hists__add_entry(self, al, NULL, period) != NULL)
29		return 0;
30	return -ENOMEM;
31}
32
33static int diff__process_sample_event(event_t *event, struct perf_session *session)
34{
35	struct addr_location al;
36	struct sample_data data = { .period = 1, };
37
38	if (event__preprocess_sample(event, session, &al, &data, NULL) < 0) {
39		pr_warning("problem processing %d event, skipping it.\n",
40			   event->header.type);
41		return -1;
42	}
43
44	if (al.filtered || al.sym == NULL)
45		return 0;
46
47	if (hists__add_entry(&session->hists, &al, data.period)) {
48		pr_warning("problem incrementing symbol period, skipping event\n");
49		return -1;
50	}
51
52	session->hists.stats.total_period += data.period;
53	return 0;
54}
55
56static struct perf_event_ops event_ops = {
57	.sample	= diff__process_sample_event,
58	.mmap	= event__process_mmap,
59	.comm	= event__process_comm,
60	.exit	= event__process_task,
61	.fork	= event__process_task,
62	.lost	= event__process_lost,
63};
64
65static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
66						    struct hist_entry *he)
67{
68	struct rb_node **p = &root->rb_node;
69	struct rb_node *parent = NULL;
70	struct hist_entry *iter;
71
72	while (*p != NULL) {
73		parent = *p;
74		iter = rb_entry(parent, struct hist_entry, rb_node);
75		if (hist_entry__cmp(he, iter) < 0)
76			p = &(*p)->rb_left;
77		else
78			p = &(*p)->rb_right;
79	}
80
81	rb_link_node(&he->rb_node, parent, p);
82	rb_insert_color(&he->rb_node, root);
83}
84
85static void hists__resort_entries(struct hists *self)
86{
87	unsigned long position = 1;
88	struct rb_root tmp = RB_ROOT;
89	struct rb_node *next = rb_first(&self->entries);
90
91	while (next != NULL) {
92		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
93
94		next = rb_next(&n->rb_node);
95		rb_erase(&n->rb_node, &self->entries);
96		n->position = position++;
97		perf_session__insert_hist_entry_by_name(&tmp, n);
98	}
99
100	self->entries = tmp;
101}
102
103static void hists__set_positions(struct hists *self)
104{
105	hists__output_resort(self);
106	hists__resort_entries(self);
107}
108
109static struct hist_entry *hists__find_entry(struct hists *self,
110					    struct hist_entry *he)
111{
112	struct rb_node *n = self->entries.rb_node;
113
114	while (n) {
115		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
116		int64_t cmp = hist_entry__cmp(he, iter);
117
118		if (cmp < 0)
119			n = n->rb_left;
120		else if (cmp > 0)
121			n = n->rb_right;
122		else
123			return iter;
124	}
125
126	return NULL;
127}
128
129static void hists__match(struct hists *older, struct hists *newer)
130{
131	struct rb_node *nd;
132
133	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
134		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
135		pos->pair = hists__find_entry(older, pos);
136	}
137}
138
139static int __cmd_diff(void)
140{
141	int ret, i;
142	struct perf_session *session[2];
143
144	session[0] = perf_session__new(input_old, O_RDONLY, force, false);
145	session[1] = perf_session__new(input_new, O_RDONLY, force, false);
146	if (session[0] == NULL || session[1] == NULL)
147		return -ENOMEM;
148
149	for (i = 0; i < 2; ++i) {
150		ret = perf_session__process_events(session[i], &event_ops);
151		if (ret)
152			goto out_delete;
153	}
154
155	hists__output_resort(&session[1]->hists);
156	if (show_displacement)
157		hists__set_positions(&session[0]->hists);
158
159	hists__match(&session[0]->hists, &session[1]->hists);
160	hists__fprintf(&session[1]->hists, &session[0]->hists,
161		       show_displacement, stdout);
162out_delete:
163	for (i = 0; i < 2; ++i)
164		perf_session__delete(session[i]);
165	return ret;
166}
167
168static const char * const diff_usage[] = {
169	"perf diff [<options>] [old_file] [new_file]",
170	NULL,
171};
172
173static const struct option options[] = {
174	OPT_INCR('v', "verbose", &verbose,
175		    "be more verbose (show symbol address, etc)"),
176	OPT_BOOLEAN('m', "displacement", &show_displacement,
177		    "Show position displacement relative to baseline"),
178	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
179		    "dump raw trace in ASCII"),
180	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
181	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
182		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
183	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
184		   "only consider symbols in these dsos"),
185	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
186		   "only consider symbols in these comms"),
187	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
188		   "only consider these symbols"),
189	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
190		   "sort by key(s): pid, comm, dso, symbol, parent"),
191	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
192		   "separator for columns, no spaces will be added between "
193		   "columns '.' is reserved."),
194	OPT_END()
195};
196
197int cmd_diff(int argc, const char **argv, const char *prefix __used)
198{
199	sort_order = diff__default_sort_order;
200	argc = parse_options(argc, argv, options, diff_usage, 0);
201	if (argc) {
202		if (argc > 2)
203			usage_with_options(diff_usage, options);
204		if (argc == 2) {
205			input_old = argv[0];
206			input_new = argv[1];
207		} else
208			input_new = argv[0];
209	} else if (symbol_conf.default_guest_vmlinux_name ||
210		   symbol_conf.default_guest_kallsyms) {
211		input_old = "perf.data.host";
212		input_new = "perf.data.guest";
213	}
214
215	symbol_conf.exclude_other = false;
216	if (symbol__init() < 0)
217		return -1;
218
219	setup_sorting(diff_usage, options);
220	setup_pager();
221
222	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
223	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
224	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
225
226	return __cmd_diff();
227}
228