xref: /linux/tools/perf/builtin-diff.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
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, al, NULL,
30 							       count, &hit);
31 	if (he == NULL)
32 		return -ENOMEM;
33 
34 	if (hit)
35 		he->count += count;
36 
37 	return 0;
38 }
39 
40 static int diff__process_sample_event(event_t *event, struct perf_session *session)
41 {
42 	struct addr_location al;
43 	struct sample_data data = { .period = 1, };
44 
45 	dump_printf("(IP, %d): %d: %#Lx\n", event->header.misc,
46 		    event->ip.pid, event->ip.ip);
47 
48 	if (event__preprocess_sample(event, session, &al, NULL) < 0) {
49 		pr_warning("problem processing %d event, skipping it.\n",
50 			   event->header.type);
51 		return -1;
52 	}
53 
54 	if (al.filtered || al.sym == NULL)
55 		return 0;
56 
57 	event__parse_sample(event, session->sample_type, &data);
58 
59 	if (perf_session__add_hist_entry(session, &al, data.period)) {
60 		pr_warning("problem incrementing symbol count, skipping event\n");
61 		return -1;
62 	}
63 
64 	session->events_stats.total += data.period;
65 	return 0;
66 }
67 
68 static struct perf_event_ops event_ops = {
69 	.sample	= diff__process_sample_event,
70 	.mmap	= event__process_mmap,
71 	.comm	= event__process_comm,
72 	.exit	= event__process_task,
73 	.fork	= event__process_task,
74 	.lost	= event__process_lost,
75 };
76 
77 static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
78 						    struct hist_entry *he)
79 {
80 	struct rb_node **p = &root->rb_node;
81 	struct rb_node *parent = NULL;
82 	struct hist_entry *iter;
83 
84 	while (*p != NULL) {
85 		parent = *p;
86 		iter = rb_entry(parent, struct hist_entry, rb_node);
87 		if (hist_entry__cmp(he, iter) < 0)
88 			p = &(*p)->rb_left;
89 		else
90 			p = &(*p)->rb_right;
91 	}
92 
93 	rb_link_node(&he->rb_node, parent, p);
94 	rb_insert_color(&he->rb_node, root);
95 }
96 
97 static void perf_session__resort_hist_entries(struct perf_session *self)
98 {
99 	unsigned long position = 1;
100 	struct rb_root tmp = RB_ROOT;
101 	struct rb_node *next = rb_first(&self->hists);
102 
103 	while (next != NULL) {
104 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
105 
106 		next = rb_next(&n->rb_node);
107 		rb_erase(&n->rb_node, &self->hists);
108 		n->position = position++;
109 		perf_session__insert_hist_entry_by_name(&tmp, n);
110 	}
111 
112 	self->hists = tmp;
113 }
114 
115 static void perf_session__set_hist_entries_positions(struct perf_session *self)
116 {
117 	perf_session__output_resort(self, self->events_stats.total);
118 	perf_session__resort_hist_entries(self);
119 }
120 
121 static struct hist_entry *
122 perf_session__find_hist_entry(struct perf_session *self,
123 			      struct hist_entry *he)
124 {
125 	struct rb_node *n = self->hists.rb_node;
126 
127 	while (n) {
128 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
129 		int64_t cmp = hist_entry__cmp(he, iter);
130 
131 		if (cmp < 0)
132 			n = n->rb_left;
133 		else if (cmp > 0)
134 			n = n->rb_right;
135 		else
136 			return iter;
137 	}
138 
139 	return NULL;
140 }
141 
142 static void perf_session__match_hists(struct perf_session *old_session,
143 				      struct perf_session *new_session)
144 {
145 	struct rb_node *nd;
146 
147 	for (nd = rb_first(&new_session->hists); nd; nd = rb_next(nd)) {
148 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
149 		pos->pair = perf_session__find_hist_entry(old_session, pos);
150 	}
151 }
152 
153 static int __cmd_diff(void)
154 {
155 	int ret, i;
156 	struct perf_session *session[2];
157 
158 	session[0] = perf_session__new(input_old, O_RDONLY, force);
159 	session[1] = perf_session__new(input_new, O_RDONLY, force);
160 	if (session[0] == NULL || session[1] == NULL)
161 		return -ENOMEM;
162 
163 	for (i = 0; i < 2; ++i) {
164 		ret = perf_session__process_events(session[i], &event_ops);
165 		if (ret)
166 			goto out_delete;
167 	}
168 
169 	perf_session__output_resort(session[1], session[1]->events_stats.total);
170 	if (show_displacement)
171 		perf_session__set_hist_entries_positions(session[0]);
172 
173 	perf_session__match_hists(session[0], session[1]);
174 	perf_session__fprintf_hists(session[1], session[0],
175 				    show_displacement, stdout);
176 out_delete:
177 	for (i = 0; i < 2; ++i)
178 		perf_session__delete(session[i]);
179 	return ret;
180 }
181 
182 static const char * const diff_usage[] = {
183 	"perf diff [<options>] [old_file] [new_file]",
184 	NULL,
185 };
186 
187 static const struct option options[] = {
188 	OPT_BOOLEAN('v', "verbose", &verbose,
189 		    "be more verbose (show symbol address, etc)"),
190 	OPT_BOOLEAN('m', "displacement", &show_displacement,
191 		    "Show position displacement relative to baseline"),
192 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
193 		    "dump raw trace in ASCII"),
194 	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
195 	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
196 		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
197 	OPT_BOOLEAN('P', "full-paths", &symbol_conf.full_paths,
198 		    "Don't shorten the pathnames taking into account the cwd"),
199 	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
200 		   "only consider symbols in these dsos"),
201 	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
202 		   "only consider symbols in these comms"),
203 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
204 		   "only consider these symbols"),
205 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
206 		   "sort by key(s): pid, comm, dso, symbol, parent"),
207 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
208 		   "separator for columns, no spaces will be added between "
209 		   "columns '.' is reserved."),
210 	OPT_END()
211 };
212 
213 int cmd_diff(int argc, const char **argv, const char *prefix __used)
214 {
215 	sort_order = diff__default_sort_order;
216 	argc = parse_options(argc, argv, options, diff_usage, 0);
217 	if (argc) {
218 		if (argc > 2)
219 			usage_with_options(diff_usage, options);
220 		if (argc == 2) {
221 			input_old = argv[0];
222 			input_new = argv[1];
223 		} else
224 			input_new = argv[0];
225 	}
226 
227 	symbol_conf.exclude_other = false;
228 	if (symbol__init() < 0)
229 		return -1;
230 
231 	setup_sorting(diff_usage, options);
232 	setup_pager();
233 
234 	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
235 	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
236 	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
237 
238 	return __cmd_diff();
239 }
240