xref: /linux/tools/perf/builtin-diff.c (revision 3b64b1881143ce9e461c211cc81acc72d0cdc476)
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/evsel.h"
13 #include "util/evlist.h"
14 #include "util/session.h"
15 #include "util/tool.h"
16 #include "util/sort.h"
17 #include "util/symbol.h"
18 #include "util/util.h"
19 
20 #include <stdlib.h>
21 
22 static char const *input_old = "perf.data.old",
23 		  *input_new = "perf.data";
24 static char	  diff__default_sort_order[] = "dso,symbol";
25 static bool  force;
26 static bool show_displacement;
27 
28 static int hists__add_entry(struct hists *self,
29 			    struct addr_location *al, u64 period)
30 {
31 	if (__hists__add_entry(self, al, NULL, period) != NULL)
32 		return 0;
33 	return -ENOMEM;
34 }
35 
36 static int diff__process_sample_event(struct perf_tool *tool __maybe_unused,
37 				      union perf_event *event,
38 				      struct perf_sample *sample,
39 				      struct perf_evsel *evsel,
40 				      struct machine *machine)
41 {
42 	struct addr_location al;
43 
44 	if (perf_event__preprocess_sample(event, machine, &al, sample, NULL) < 0) {
45 		pr_warning("problem processing %d event, skipping it.\n",
46 			   event->header.type);
47 		return -1;
48 	}
49 
50 	if (al.filtered || al.sym == NULL)
51 		return 0;
52 
53 	if (hists__add_entry(&evsel->hists, &al, sample->period)) {
54 		pr_warning("problem incrementing symbol period, skipping event\n");
55 		return -1;
56 	}
57 
58 	evsel->hists.stats.total_period += sample->period;
59 	return 0;
60 }
61 
62 static struct perf_tool tool = {
63 	.sample	= diff__process_sample_event,
64 	.mmap	= perf_event__process_mmap,
65 	.comm	= perf_event__process_comm,
66 	.exit	= perf_event__process_task,
67 	.fork	= perf_event__process_task,
68 	.lost	= perf_event__process_lost,
69 	.ordered_samples = true,
70 	.ordering_requires_timestamps = true,
71 };
72 
73 static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
74 						    struct hist_entry *he)
75 {
76 	struct rb_node **p = &root->rb_node;
77 	struct rb_node *parent = NULL;
78 	struct hist_entry *iter;
79 
80 	while (*p != NULL) {
81 		parent = *p;
82 		iter = rb_entry(parent, struct hist_entry, rb_node);
83 		if (hist_entry__cmp(he, iter) < 0)
84 			p = &(*p)->rb_left;
85 		else
86 			p = &(*p)->rb_right;
87 	}
88 
89 	rb_link_node(&he->rb_node, parent, p);
90 	rb_insert_color(&he->rb_node, root);
91 }
92 
93 static void hists__resort_entries(struct hists *self)
94 {
95 	unsigned long position = 1;
96 	struct rb_root tmp = RB_ROOT;
97 	struct rb_node *next = rb_first(&self->entries);
98 
99 	while (next != NULL) {
100 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
101 
102 		next = rb_next(&n->rb_node);
103 		rb_erase(&n->rb_node, &self->entries);
104 		n->position = position++;
105 		perf_session__insert_hist_entry_by_name(&tmp, n);
106 	}
107 
108 	self->entries = tmp;
109 }
110 
111 static struct hist_entry *hists__find_entry(struct hists *self,
112 					    struct hist_entry *he)
113 {
114 	struct rb_node *n = self->entries.rb_node;
115 
116 	while (n) {
117 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
118 		int64_t cmp = hist_entry__cmp(he, iter);
119 
120 		if (cmp < 0)
121 			n = n->rb_left;
122 		else if (cmp > 0)
123 			n = n->rb_right;
124 		else
125 			return iter;
126 	}
127 
128 	return NULL;
129 }
130 
131 static void hists__match(struct hists *older, struct hists *newer)
132 {
133 	struct rb_node *nd;
134 
135 	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
136 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
137 		pos->pair = hists__find_entry(older, pos);
138 	}
139 }
140 
141 static struct perf_evsel *evsel_match(struct perf_evsel *evsel,
142 				      struct perf_evlist *evlist)
143 {
144 	struct perf_evsel *e;
145 
146 	list_for_each_entry(e, &evlist->entries, node)
147 		if (perf_evsel__match2(evsel, e))
148 			return e;
149 
150 	return NULL;
151 }
152 
153 static int __cmd_diff(void)
154 {
155 	int ret, i;
156 #define older (session[0])
157 #define newer (session[1])
158 	struct perf_session *session[2];
159 	struct perf_evlist *evlist_new, *evlist_old;
160 	struct perf_evsel *evsel;
161 	bool first = true;
162 
163 	older = perf_session__new(input_old, O_RDONLY, force, false,
164 				  &tool);
165 	newer = perf_session__new(input_new, O_RDONLY, force, false,
166 				  &tool);
167 	if (session[0] == NULL || session[1] == NULL)
168 		return -ENOMEM;
169 
170 	for (i = 0; i < 2; ++i) {
171 		ret = perf_session__process_events(session[i], &tool);
172 		if (ret)
173 			goto out_delete;
174 	}
175 
176 	evlist_old = older->evlist;
177 	evlist_new = newer->evlist;
178 
179 	list_for_each_entry(evsel, &evlist_new->entries, node)
180 		hists__output_resort(&evsel->hists);
181 
182 	list_for_each_entry(evsel, &evlist_old->entries, node) {
183 		hists__output_resort(&evsel->hists);
184 
185 		if (show_displacement)
186 			hists__resort_entries(&evsel->hists);
187 	}
188 
189 	list_for_each_entry(evsel, &evlist_new->entries, node) {
190 		struct perf_evsel *evsel_old;
191 
192 		evsel_old = evsel_match(evsel, evlist_old);
193 		if (!evsel_old)
194 			continue;
195 
196 		fprintf(stdout, "%s# Event '%s'\n#\n", first ? "" : "\n",
197 			perf_evsel__name(evsel));
198 
199 		first = false;
200 
201 		hists__match(&evsel_old->hists, &evsel->hists);
202 		hists__fprintf(&evsel->hists, &evsel_old->hists,
203 			       show_displacement, true, 0, 0, stdout);
204 	}
205 
206 out_delete:
207 	for (i = 0; i < 2; ++i)
208 		perf_session__delete(session[i]);
209 	return ret;
210 #undef older
211 #undef newer
212 }
213 
214 static const char * const diff_usage[] = {
215 	"perf diff [<options>] [old_file] [new_file]",
216 	NULL,
217 };
218 
219 static const struct option options[] = {
220 	OPT_INCR('v', "verbose", &verbose,
221 		    "be more verbose (show symbol address, etc)"),
222 	OPT_BOOLEAN('M', "displacement", &show_displacement,
223 		    "Show position displacement relative to baseline"),
224 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
225 		    "dump raw trace in ASCII"),
226 	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
227 	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
228 		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
229 	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
230 		   "only consider symbols in these dsos"),
231 	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
232 		   "only consider symbols in these comms"),
233 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
234 		   "only consider these symbols"),
235 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
236 		   "sort by key(s): pid, comm, dso, symbol, parent"),
237 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
238 		   "separator for columns, no spaces will be added between "
239 		   "columns '.' is reserved."),
240 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
241 		    "Look for files with symbols relative to this directory"),
242 	OPT_END()
243 };
244 
245 int cmd_diff(int argc, const char **argv, const char *prefix __maybe_unused)
246 {
247 	sort_order = diff__default_sort_order;
248 	argc = parse_options(argc, argv, options, diff_usage, 0);
249 	if (argc) {
250 		if (argc > 2)
251 			usage_with_options(diff_usage, options);
252 		if (argc == 2) {
253 			input_old = argv[0];
254 			input_new = argv[1];
255 		} else
256 			input_new = argv[0];
257 	} else if (symbol_conf.default_guest_vmlinux_name ||
258 		   symbol_conf.default_guest_kallsyms) {
259 		input_old = "perf.data.host";
260 		input_new = "perf.data.guest";
261 	}
262 
263 	symbol_conf.exclude_other = false;
264 	if (symbol__init() < 0)
265 		return -1;
266 
267 	perf_hpp__init(true, show_displacement);
268 	setup_sorting(diff_usage, options);
269 	setup_pager();
270 
271 	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
272 	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
273 	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
274 
275 	return __cmd_diff();
276 }
277