xref: /linux/tools/perf/builtin-diff.c (revision a5c4300389bb33ade2515c082709217f0614cf15)
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 bool  force;
23 static bool show_displacement;
24 
25 static 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 
33 static 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 	dump_printf("(IP, %d): %d: %#Lx\n", event->header.misc,
39 		    event->ip.pid, event->ip.ip);
40 
41 	if (event__preprocess_sample(event, session, &al, NULL) < 0) {
42 		pr_warning("problem processing %d event, skipping it.\n",
43 			   event->header.type);
44 		return -1;
45 	}
46 
47 	if (al.filtered || al.sym == NULL)
48 		return 0;
49 
50 	event__parse_sample(event, session->sample_type, &data);
51 
52 	if (hists__add_entry(&session->hists, &al, data.period)) {
53 		pr_warning("problem incrementing symbol period, skipping event\n");
54 		return -1;
55 	}
56 
57 	session->hists.stats.total_period += data.period;
58 	return 0;
59 }
60 
61 static struct perf_event_ops event_ops = {
62 	.sample	= diff__process_sample_event,
63 	.mmap	= event__process_mmap,
64 	.comm	= event__process_comm,
65 	.exit	= event__process_task,
66 	.fork	= event__process_task,
67 	.lost	= event__process_lost,
68 };
69 
70 static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
71 						    struct hist_entry *he)
72 {
73 	struct rb_node **p = &root->rb_node;
74 	struct rb_node *parent = NULL;
75 	struct hist_entry *iter;
76 
77 	while (*p != NULL) {
78 		parent = *p;
79 		iter = rb_entry(parent, struct hist_entry, rb_node);
80 		if (hist_entry__cmp(he, iter) < 0)
81 			p = &(*p)->rb_left;
82 		else
83 			p = &(*p)->rb_right;
84 	}
85 
86 	rb_link_node(&he->rb_node, parent, p);
87 	rb_insert_color(&he->rb_node, root);
88 }
89 
90 static void hists__resort_entries(struct hists *self)
91 {
92 	unsigned long position = 1;
93 	struct rb_root tmp = RB_ROOT;
94 	struct rb_node *next = rb_first(&self->entries);
95 
96 	while (next != NULL) {
97 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
98 
99 		next = rb_next(&n->rb_node);
100 		rb_erase(&n->rb_node, &self->entries);
101 		n->position = position++;
102 		perf_session__insert_hist_entry_by_name(&tmp, n);
103 	}
104 
105 	self->entries = tmp;
106 }
107 
108 static void hists__set_positions(struct hists *self)
109 {
110 	hists__output_resort(self);
111 	hists__resort_entries(self);
112 }
113 
114 static struct hist_entry *hists__find_entry(struct hists *self,
115 					    struct hist_entry *he)
116 {
117 	struct rb_node *n = self->entries.rb_node;
118 
119 	while (n) {
120 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
121 		int64_t cmp = hist_entry__cmp(he, iter);
122 
123 		if (cmp < 0)
124 			n = n->rb_left;
125 		else if (cmp > 0)
126 			n = n->rb_right;
127 		else
128 			return iter;
129 	}
130 
131 	return NULL;
132 }
133 
134 static void hists__match(struct hists *older, struct hists *newer)
135 {
136 	struct rb_node *nd;
137 
138 	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
139 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
140 		pos->pair = hists__find_entry(older, pos);
141 	}
142 }
143 
144 static int __cmd_diff(void)
145 {
146 	int ret, i;
147 	struct perf_session *session[2];
148 
149 	session[0] = perf_session__new(input_old, O_RDONLY, force, false);
150 	session[1] = perf_session__new(input_new, O_RDONLY, force, false);
151 	if (session[0] == NULL || session[1] == NULL)
152 		return -ENOMEM;
153 
154 	for (i = 0; i < 2; ++i) {
155 		ret = perf_session__process_events(session[i], &event_ops);
156 		if (ret)
157 			goto out_delete;
158 	}
159 
160 	hists__output_resort(&session[1]->hists);
161 	if (show_displacement)
162 		hists__set_positions(&session[0]->hists);
163 
164 	hists__match(&session[0]->hists, &session[1]->hists);
165 	hists__fprintf(&session[1]->hists, &session[0]->hists,
166 		       show_displacement, stdout);
167 out_delete:
168 	for (i = 0; i < 2; ++i)
169 		perf_session__delete(session[i]);
170 	return ret;
171 }
172 
173 static const char * const diff_usage[] = {
174 	"perf diff [<options>] [old_file] [new_file]",
175 	NULL,
176 };
177 
178 static const struct option options[] = {
179 	OPT_INCR('v', "verbose", &verbose,
180 		    "be more verbose (show symbol address, etc)"),
181 	OPT_BOOLEAN('m', "displacement", &show_displacement,
182 		    "Show position displacement relative to baseline"),
183 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
184 		    "dump raw trace in ASCII"),
185 	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
186 	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
187 		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
188 	OPT_BOOLEAN('P', "full-paths", &symbol_conf.full_paths,
189 		    "Don't shorten the pathnames taking into account the cwd"),
190 	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
191 		   "only consider symbols in these dsos"),
192 	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
193 		   "only consider symbols in these comms"),
194 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
195 		   "only consider these symbols"),
196 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
197 		   "sort by key(s): pid, comm, dso, symbol, parent"),
198 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
199 		   "separator for columns, no spaces will be added between "
200 		   "columns '.' is reserved."),
201 	OPT_END()
202 };
203 
204 int cmd_diff(int argc, const char **argv, const char *prefix __used)
205 {
206 	sort_order = diff__default_sort_order;
207 	argc = parse_options(argc, argv, options, diff_usage, 0);
208 	if (argc) {
209 		if (argc > 2)
210 			usage_with_options(diff_usage, options);
211 		if (argc == 2) {
212 			input_old = argv[0];
213 			input_new = argv[1];
214 		} else
215 			input_new = argv[0];
216 	} else if (symbol_conf.default_guest_vmlinux_name ||
217 		   symbol_conf.default_guest_kallsyms) {
218 		input_old = "perf.data.host";
219 		input_new = "perf.data.guest";
220 	}
221 
222 	symbol_conf.exclude_other = false;
223 	if (symbol__init() < 0)
224 		return -1;
225 
226 	setup_sorting(diff_usage, options);
227 	setup_pager();
228 
229 	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
230 	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
231 	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
232 
233 	return __cmd_diff();
234 }
235