xref: /openbmc/linux/tools/perf/builtin-diff.c (revision 7fe2f639)
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(union perf_event *event,
34 				      struct perf_sample *sample,
35 				      struct perf_evsel *evsel __used,
36 				      struct perf_session *session)
37 {
38 	struct addr_location al;
39 
40 	if (perf_event__preprocess_sample(event, session, &al, sample, NULL) < 0) {
41 		pr_warning("problem processing %d event, skipping it.\n",
42 			   event->header.type);
43 		return -1;
44 	}
45 
46 	if (al.filtered || al.sym == NULL)
47 		return 0;
48 
49 	if (hists__add_entry(&session->hists, &al, sample->period)) {
50 		pr_warning("problem incrementing symbol period, skipping event\n");
51 		return -1;
52 	}
53 
54 	session->hists.stats.total_period += sample->period;
55 	return 0;
56 }
57 
58 static struct perf_event_ops event_ops = {
59 	.sample	= diff__process_sample_event,
60 	.mmap	= perf_event__process_mmap,
61 	.comm	= perf_event__process_comm,
62 	.exit	= perf_event__process_task,
63 	.fork	= perf_event__process_task,
64 	.lost	= perf_event__process_lost,
65 	.ordered_samples = true,
66 	.ordering_requires_timestamps = true,
67 };
68 
69 static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
70 						    struct hist_entry *he)
71 {
72 	struct rb_node **p = &root->rb_node;
73 	struct rb_node *parent = NULL;
74 	struct hist_entry *iter;
75 
76 	while (*p != NULL) {
77 		parent = *p;
78 		iter = rb_entry(parent, struct hist_entry, rb_node);
79 		if (hist_entry__cmp(he, iter) < 0)
80 			p = &(*p)->rb_left;
81 		else
82 			p = &(*p)->rb_right;
83 	}
84 
85 	rb_link_node(&he->rb_node, parent, p);
86 	rb_insert_color(&he->rb_node, root);
87 }
88 
89 static void hists__resort_entries(struct hists *self)
90 {
91 	unsigned long position = 1;
92 	struct rb_root tmp = RB_ROOT;
93 	struct rb_node *next = rb_first(&self->entries);
94 
95 	while (next != NULL) {
96 		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
97 
98 		next = rb_next(&n->rb_node);
99 		rb_erase(&n->rb_node, &self->entries);
100 		n->position = position++;
101 		perf_session__insert_hist_entry_by_name(&tmp, n);
102 	}
103 
104 	self->entries = tmp;
105 }
106 
107 static void hists__set_positions(struct hists *self)
108 {
109 	hists__output_resort(self);
110 	hists__resort_entries(self);
111 }
112 
113 static struct hist_entry *hists__find_entry(struct hists *self,
114 					    struct hist_entry *he)
115 {
116 	struct rb_node *n = self->entries.rb_node;
117 
118 	while (n) {
119 		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
120 		int64_t cmp = hist_entry__cmp(he, iter);
121 
122 		if (cmp < 0)
123 			n = n->rb_left;
124 		else if (cmp > 0)
125 			n = n->rb_right;
126 		else
127 			return iter;
128 	}
129 
130 	return NULL;
131 }
132 
133 static void hists__match(struct hists *older, struct hists *newer)
134 {
135 	struct rb_node *nd;
136 
137 	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
138 		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
139 		pos->pair = hists__find_entry(older, pos);
140 	}
141 }
142 
143 static int __cmd_diff(void)
144 {
145 	int ret, i;
146 	struct perf_session *session[2];
147 
148 	session[0] = perf_session__new(input_old, O_RDONLY, force, false, &event_ops);
149 	session[1] = perf_session__new(input_new, O_RDONLY, force, false, &event_ops);
150 	if (session[0] == NULL || session[1] == NULL)
151 		return -ENOMEM;
152 
153 	for (i = 0; i < 2; ++i) {
154 		ret = perf_session__process_events(session[i], &event_ops);
155 		if (ret)
156 			goto out_delete;
157 	}
158 
159 	hists__output_resort(&session[1]->hists);
160 	if (show_displacement)
161 		hists__set_positions(&session[0]->hists);
162 
163 	hists__match(&session[0]->hists, &session[1]->hists);
164 	hists__fprintf(&session[1]->hists, &session[0]->hists,
165 		       show_displacement, stdout);
166 out_delete:
167 	for (i = 0; i < 2; ++i)
168 		perf_session__delete(session[i]);
169 	return ret;
170 }
171 
172 static const char * const diff_usage[] = {
173 	"perf diff [<options>] [old_file] [new_file]",
174 	NULL,
175 };
176 
177 static const struct option options[] = {
178 	OPT_INCR('v', "verbose", &verbose,
179 		    "be more verbose (show symbol address, etc)"),
180 	OPT_BOOLEAN('M', "displacement", &show_displacement,
181 		    "Show position displacement relative to baseline"),
182 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
183 		    "dump raw trace in ASCII"),
184 	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
185 	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
186 		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
187 	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
188 		   "only consider symbols in these dsos"),
189 	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
190 		   "only consider symbols in these comms"),
191 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
192 		   "only consider these symbols"),
193 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
194 		   "sort by key(s): pid, comm, dso, symbol, parent"),
195 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
196 		   "separator for columns, no spaces will be added between "
197 		   "columns '.' is reserved."),
198 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
199 		    "Look for files with symbols relative to this directory"),
200 	OPT_END()
201 };
202 
203 int cmd_diff(int argc, const char **argv, const char *prefix __used)
204 {
205 	sort_order = diff__default_sort_order;
206 	argc = parse_options(argc, argv, options, diff_usage, 0);
207 	if (argc) {
208 		if (argc > 2)
209 			usage_with_options(diff_usage, options);
210 		if (argc == 2) {
211 			input_old = argv[0];
212 			input_new = argv[1];
213 		} else
214 			input_new = argv[0];
215 	} else if (symbol_conf.default_guest_vmlinux_name ||
216 		   symbol_conf.default_guest_kallsyms) {
217 		input_old = "perf.data.host";
218 		input_new = "perf.data.guest";
219 	}
220 
221 	symbol_conf.exclude_other = false;
222 	if (symbol__init() < 0)
223 		return -1;
224 
225 	setup_sorting(diff_usage, options);
226 	setup_pager();
227 
228 	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
229 	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
230 	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
231 
232 	return __cmd_diff();
233 }
234