xref: /linux/tools/perf/builtin-diff.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 
19 static char const *input_old = "perf.data.old",
20 		  *input_new = "perf.data";
21 static char	  diff__default_sort_order[] = "dso,symbol";
22 static int  force;
23 static bool show_displacement;
24 
25 static int perf_session__add_hist_entry(struct perf_session *self,
26 					struct addr_location *al, u64 count)
27 {
28 	bool hit;
29 	struct hist_entry *he = __perf_session__add_hist_entry(&self->hists,
30 							       al, NULL,
31 							       count, &hit);
32 	if (he == NULL)
33 		return -ENOMEM;
34 
35 	if (hit)
36 		he->count += count;
37 
38 	return 0;
39 }
40 
41 static int diff__process_sample_event(event_t *event, struct perf_session *session)
42 {
43 	struct addr_location al;
44 	struct sample_data data = { .period = 1, };
45 
46 	dump_printf("(IP, %d): %d: %#Lx\n", event->header.misc,
47 		    event->ip.pid, event->ip.ip);
48 
49 	if (event__preprocess_sample(event, session, &al, NULL) < 0) {
50 		pr_warning("problem processing %d event, skipping it.\n",
51 			   event->header.type);
52 		return -1;
53 	}
54 
55 	if (al.filtered || al.sym == NULL)
56 		return 0;
57 
58 	event__parse_sample(event, session->sample_type, &data);
59 
60 	if (perf_session__add_hist_entry(session, &al, data.period)) {
61 		pr_warning("problem incrementing symbol count, skipping event\n");
62 		return -1;
63 	}
64 
65 	session->events_stats.total += data.period;
66 	return 0;
67 }
68 
69 static struct perf_event_ops event_ops = {
70 	.sample	= diff__process_sample_event,
71 	.mmap	= event__process_mmap,
72 	.comm	= event__process_comm,
73 	.exit	= event__process_task,
74 	.fork	= event__process_task,
75 	.lost	= event__process_lost,
76 };
77 
78 static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
79 						    struct hist_entry *he)
80 {
81 	struct rb_node **p = &root->rb_node;
82 	struct rb_node *parent = NULL;
83 	struct hist_entry *iter;
84 
85 	while (*p != NULL) {
86 		parent = *p;
87 		iter = rb_entry(parent, struct hist_entry, rb_node);
88 		if (hist_entry__cmp(he, iter) < 0)
89 			p = &(*p)->rb_left;
90 		else
91 			p = &(*p)->rb_right;
92 	}
93 
94 	rb_link_node(&he->rb_node, parent, p);
95 	rb_insert_color(&he->rb_node, root);
96 }
97 
98 static void perf_session__resort_hist_entries(struct perf_session *self)
99 {
100 	unsigned long position = 1;
101 	struct rb_root tmp = RB_ROOT;
102 	struct rb_node *next = rb_first(&self->hists);
103 
104 	while (next != NULL) {
105 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
106 
107 		next = rb_next(&n->rb_node);
108 		rb_erase(&n->rb_node, &self->hists);
109 		n->position = position++;
110 		perf_session__insert_hist_entry_by_name(&tmp, n);
111 	}
112 
113 	self->hists = tmp;
114 }
115 
116 static void perf_session__set_hist_entries_positions(struct perf_session *self)
117 {
118 	perf_session__output_resort(&self->hists, self->events_stats.total);
119 	perf_session__resort_hist_entries(self);
120 }
121 
122 static struct hist_entry *
123 perf_session__find_hist_entry(struct perf_session *self,
124 			      struct hist_entry *he)
125 {
126 	struct rb_node *n = self->hists.rb_node;
127 
128 	while (n) {
129 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
130 		int64_t cmp = hist_entry__cmp(he, iter);
131 
132 		if (cmp < 0)
133 			n = n->rb_left;
134 		else if (cmp > 0)
135 			n = n->rb_right;
136 		else
137 			return iter;
138 	}
139 
140 	return NULL;
141 }
142 
143 static void perf_session__match_hists(struct perf_session *old_session,
144 				      struct perf_session *new_session)
145 {
146 	struct rb_node *nd;
147 
148 	for (nd = rb_first(&new_session->hists); nd; nd = rb_next(nd)) {
149 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
150 		pos->pair = perf_session__find_hist_entry(old_session, pos);
151 	}
152 }
153 
154 static int __cmd_diff(void)
155 {
156 	int ret, i;
157 	struct perf_session *session[2];
158 
159 	session[0] = perf_session__new(input_old, O_RDONLY, force);
160 	session[1] = perf_session__new(input_new, O_RDONLY, force);
161 	if (session[0] == NULL || session[1] == NULL)
162 		return -ENOMEM;
163 
164 	for (i = 0; i < 2; ++i) {
165 		ret = perf_session__process_events(session[i], &event_ops);
166 		if (ret)
167 			goto out_delete;
168 	}
169 
170 	perf_session__output_resort(&session[1]->hists,
171 				    session[1]->events_stats.total);
172 	if (show_displacement)
173 		perf_session__set_hist_entries_positions(session[0]);
174 
175 	perf_session__match_hists(session[0], session[1]);
176 	perf_session__fprintf_hists(&session[1]->hists, session[0],
177 				    show_displacement, stdout,
178 				    session[1]->events_stats.total);
179 out_delete:
180 	for (i = 0; i < 2; ++i)
181 		perf_session__delete(session[i]);
182 	return ret;
183 }
184 
185 static const char * const diff_usage[] = {
186 	"perf diff [<options>] [old_file] [new_file]",
187 	NULL,
188 };
189 
190 static const struct option options[] = {
191 	OPT_BOOLEAN('v', "verbose", &verbose,
192 		    "be more verbose (show symbol address, etc)"),
193 	OPT_BOOLEAN('m', "displacement", &show_displacement,
194 		    "Show position displacement relative to baseline"),
195 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
196 		    "dump raw trace in ASCII"),
197 	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
198 	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
199 		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
200 	OPT_BOOLEAN('P', "full-paths", &symbol_conf.full_paths,
201 		    "Don't shorten the pathnames taking into account the cwd"),
202 	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
203 		   "only consider symbols in these dsos"),
204 	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
205 		   "only consider symbols in these comms"),
206 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
207 		   "only consider these symbols"),
208 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
209 		   "sort by key(s): pid, comm, dso, symbol, parent"),
210 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
211 		   "separator for columns, no spaces will be added between "
212 		   "columns '.' is reserved."),
213 	OPT_END()
214 };
215 
216 int cmd_diff(int argc, const char **argv, const char *prefix __used)
217 {
218 	sort_order = diff__default_sort_order;
219 	argc = parse_options(argc, argv, options, diff_usage, 0);
220 	if (argc) {
221 		if (argc > 2)
222 			usage_with_options(diff_usage, options);
223 		if (argc == 2) {
224 			input_old = argv[0];
225 			input_new = argv[1];
226 		} else
227 			input_new = argv[0];
228 	}
229 
230 	symbol_conf.exclude_other = false;
231 	if (symbol__init() < 0)
232 		return -1;
233 
234 	setup_sorting(diff_usage, options);
235 	setup_pager();
236 
237 	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
238 	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
239 	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
240 
241 	return __cmd_diff();
242 }
243