xref: /openbmc/linux/tools/perf/builtin-diff.c (revision 7dd65feb)
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: %p\n", event->header.misc,
46 		    event->ip.pid, (void *)(long)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)
55 		return 0;
56 
57 	event__parse_sample(event, session->sample_type, &data);
58 
59 	if (al.sym && 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 	.process_sample_event = diff__process_sample_event,
70 	.process_mmap_event   = event__process_mmap,
71 	.process_comm_event   = event__process_comm,
72 	.process_exit_event   = event__process_task,
73 	.process_fork_event   = event__process_task,
74 	.process_lost_event   = 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 		int cmp;
86 		parent = *p;
87 		iter = rb_entry(parent, struct hist_entry, rb_node);
88 
89 		cmp = strcmp(he->map->dso->name, iter->map->dso->name);
90 		if (cmp > 0)
91 			p = &(*p)->rb_left;
92 		else if (cmp < 0)
93 			p = &(*p)->rb_right;
94 		else {
95 			cmp = strcmp(he->sym->name, iter->sym->name);
96 			if (cmp > 0)
97 				p = &(*p)->rb_left;
98 			else
99 				p = &(*p)->rb_right;
100 		}
101 	}
102 
103 	rb_link_node(&he->rb_node, parent, p);
104 	rb_insert_color(&he->rb_node, root);
105 }
106 
107 static void perf_session__resort_by_name(struct perf_session *self)
108 {
109 	unsigned long position = 1;
110 	struct rb_root tmp = RB_ROOT;
111 	struct rb_node *next = rb_first(&self->hists);
112 
113 	while (next != NULL) {
114 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
115 
116 		next = rb_next(&n->rb_node);
117 		rb_erase(&n->rb_node, &self->hists);
118 		n->position = position++;
119 		perf_session__insert_hist_entry_by_name(&tmp, n);
120 	}
121 
122 	self->hists = tmp;
123 }
124 
125 static struct hist_entry *
126 perf_session__find_hist_entry_by_name(struct perf_session *self,
127 				      struct hist_entry *he)
128 {
129 	struct rb_node *n = self->hists.rb_node;
130 
131 	while (n) {
132 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
133 		int cmp = strcmp(he->map->dso->name, iter->map->dso->name);
134 
135 		if (cmp > 0)
136 			n = n->rb_left;
137 		else if (cmp < 0)
138 			n = n->rb_right;
139 		else {
140 			cmp = strcmp(he->sym->name, iter->sym->name);
141 			if (cmp > 0)
142 				n = n->rb_left;
143 			else if (cmp < 0)
144 				n = n->rb_right;
145 			else
146 				return iter;
147 		}
148 	}
149 
150 	return NULL;
151 }
152 
153 static void perf_session__match_hists(struct perf_session *old_session,
154 				      struct perf_session *new_session)
155 {
156 	struct rb_node *nd;
157 
158 	perf_session__resort_by_name(old_session);
159 
160 	for (nd = rb_first(&new_session->hists); nd; nd = rb_next(nd)) {
161 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
162 		pos->pair = perf_session__find_hist_entry_by_name(old_session, pos);
163 	}
164 }
165 
166 static int __cmd_diff(void)
167 {
168 	int ret, i;
169 	struct perf_session *session[2];
170 
171 	session[0] = perf_session__new(input_old, O_RDONLY, force);
172 	session[1] = perf_session__new(input_new, O_RDONLY, force);
173 	if (session[0] == NULL || session[1] == NULL)
174 		return -ENOMEM;
175 
176 	for (i = 0; i < 2; ++i) {
177 		ret = perf_session__process_events(session[i], &event_ops);
178 		if (ret)
179 			goto out_delete;
180 		perf_session__output_resort(session[i], session[i]->events_stats.total);
181 	}
182 
183 	perf_session__match_hists(session[0], session[1]);
184 	perf_session__fprintf_hists(session[1], session[0],
185 				    show_displacement, stdout);
186 out_delete:
187 	for (i = 0; i < 2; ++i)
188 		perf_session__delete(session[i]);
189 	return ret;
190 }
191 
192 static const char * const diff_usage[] = {
193 	"perf diff [<options>] [old_file] [new_file]",
194 	NULL,
195 };
196 
197 static const struct option options[] = {
198 	OPT_BOOLEAN('v', "verbose", &verbose,
199 		    "be more verbose (show symbol address, etc)"),
200 	OPT_BOOLEAN('m', "displacement", &show_displacement,
201 		    "Show position displacement relative to baseline"),
202 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
203 		    "dump raw trace in ASCII"),
204 	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
205 	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
206 		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
207 	OPT_BOOLEAN('P', "full-paths", &event_ops.full_paths,
208 		    "Don't shorten the pathnames taking into account the cwd"),
209 	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
210 		   "only consider symbols in these dsos"),
211 	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
212 		   "only consider symbols in these comms"),
213 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
214 		   "only consider these symbols"),
215 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
216 		   "sort by key(s): pid, comm, dso, symbol, parent"),
217 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
218 		   "separator for columns, no spaces will be added between "
219 		   "columns '.' is reserved."),
220 	OPT_END()
221 };
222 
223 int cmd_diff(int argc, const char **argv, const char *prefix __used)
224 {
225 	sort_order = diff__default_sort_order;
226 	argc = parse_options(argc, argv, options, diff_usage, 0);
227 	if (argc) {
228 		if (argc > 2)
229 			usage_with_options(diff_usage, options);
230 		if (argc == 2) {
231 			input_old = argv[0];
232 			input_new = argv[1];
233 		} else
234 			input_new = argv[0];
235 	}
236 
237 	symbol_conf.exclude_other = false;
238 	if (symbol__init() < 0)
239 		return -1;
240 
241 	setup_sorting(diff_usage, options);
242 	setup_pager();
243 
244 	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
245 	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
246 	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
247 
248 	return __cmd_diff();
249 }
250